⭐ Starlight Tools Catalog

A list of all our privacy-preserving, lightweight browser-based tools. All tools run directly in your browser without uploading any data to our servers.

Tool Name Description Category Link
⭐ Add Text to Image Add text to any image. Your image never leaves your device. Image Tools Launch
⭐ Meme Generator Add top & bottom captions, drag to position, and export a PNG — all in your browser. Image Tools Launch
⭐ QR Code Generator Turn any text into a QR code instantly. Image Tools Launch
⭐ Barcode Generator Create Code-128 or EAN-13 barcodes and export as SVG/PNG. Image Tools Launch
⭐ Image Resizer & Converter Resize and convert images between various formats while preserving aspect ratio. Image Tools Launch
⭐ Batch Image Resizer & Converter Process multiple images (up to 10) in batch with global resizing and ZIP download. Image Tools Launch
⭐ Wallpaper Generator Crop once, then export wallpapers in multiple ratios & resolutions for PC, mobile, and ultrawide — all client-side with ZIP download. Image Tools Launch
⭐ Crop Image Crop any image with precision directly in your browser. No upload needed. Image Tools Launch
⭐ Compress Image Quality Compress images with adjustable quality and format. Instant preview. Fully offline. Image Tools Launch
⭐ Online Whiteboard Drawing Board A simple, client-side canvas for quick sketches, diagrams, and image export. Image Tools Launch
⭐ Image Placeholder Generator Generate custom image placeholders with dimensions and text overlay. Image Tools Launch
⭐ Image Watermark Tool Add text or logo watermarks with opacity, position, rotation, and tiling. Image Tools Launch
⭐ Flashcard Generator Create and import flashcards (CSV), edit as a list, and export a cut-ready PDF with duplex fronts/backs. Private, client-side. Graphics Launch
⭐ PDF Redaction (Burn-in) Draw boxes to permanently remove sensitive content. Burn-in redactions—private, in-browser. Document Tools Launch
⭐ PDF Reorder & Rotate Drag pages to reorder, rotate 90°/180°, delete unwanted pages, then export. Private, runs in-browser. Document Tools Launch
⭐ Markdown to PDF Convert Markdown to printable PDFs with GitHub-style rendering and syntax highlighting. All client-side, private, in-browser. Document Tools Launch
⭐ PDF to Image splitter Split a PDF file into individual images and save selected images or all of them in one click. Document Tools Launch
⭐ PDF Merger Combine multiple PDF files into one single document. No server upload. Document Tools Launch
⭐ PDF Compressor Shrink PDF files instantly in your browser—no uploads required. Document Tools Launch
⭐ PDF Text Extractor Extract all selectable text from your PDF files directly in the browser. Document Text Tools Launch
⭐ Word Counter Count words, characters, numbers, and more in your text. PDF, Document & Text Tools Launch
⭐ Text Case Converter Convert text to CAPITAL, lowercase, capitalized, sentence case, and alternating case. PDF, Document & Text Tools Launch
⭐ Alphabetic Numeric Sorter Alphabetically or numerically sort lines of text. PDF, Document & Text Tools Launch
⭐ Line Break & Whitespace Cleaner Remove all or reduce multiple line breaks and excess whitespace from your text. PDF, Document & Text Tools Launch
⭐ Duplicate Line Remover Remove identical lines from your text with options for case and whitespace. PDF, Document & Text Tools Launch
⭐ Text Diff Viewer Compare two texts and highlight differences. PDF, Document & Text Tools Launch
⭐ CSV Viewer with Filters & Sort Upload, view, sort, and filter CSV data instantly in your browser for quick analysis. PDF, Document & Text Tools Launch
⭐ Readability Score Calculator Analyze text for its readability level using Flesch-Kincaid and other metrics. Text Tools Launch
⭐ Keyword Density Checker Analyze the frequency of keywords and phrases in your text for SEO. Text Tools Launch
⭐ Text Replacement Tool Find and replace text instantly and privately in your browser. Text Tools Launch
⭐ Zalgo Glitch Text Generator Transform your text into unsettling, glitched Zalgo text. Text Tools Launch
⭐ Levenshtein Distance (Edit Distance) Compare two strings and highlight insertions, deletions, and substitutions. Text Tools Launch
⭐ GPA Calculator Calculate your GPA for high school or college, including cumulative and "what do I need" options. Utility Tools Launch
⭐ SAT↔ACT Converter & GRE↔GMAT Comparator Convert SAT↔ACT using the official 2018 concordance, and estimate GRE→GMAT (Focus & legacy) via percentile matching. Private, client-side. Education & Test Prep Launch
⭐ BMI Calculator Calculate your Body Mass Index (BMI) using imperial or metric units. Utility Tools Launch
⭐ BMI vs Body Fat % Compare BMI with estimated body fat % (US Navy & Deurenberg), metric/imperial, plus a mini chart. Utility Tools Launch
⭐ BMR Calculator Estimate your Basal Metabolic Rate (BMR) with multiple formulas and quick TDEE multipliers. Utility Tools Launch
⭐ Calorie (TDEE) Calculator Estimate your Total Daily Energy Expenditure (TDEE) with activity multipliers and calorie goals. Utility Tools Launch
⭐ Calories Burned by Activity Estimate calories burned from METs using your weight and time. Metric/imperial; private, client-side. Health & Fitness Launch
⭐ Ideal Weight Calculator Broca, Devine, Hamwi, and Robinson formulas with metric/imperial inputs and an optional ±10% frame-size adjustment. Private, client-side. Health & Fitness Launch
⭐ Blood Pressure Zone Calculator ACC/AHA (US) and NICE (UK) classification for clinic, home, or ambulatory readings, with a clear visual zone bar. Private, client-side. Science & Research Launch
⭐ Blood Sugar / HbA1c Converter NGSP % ↔ IFCC mmol/mol with eAG in mg/dL ↔ mmol/L. Clear UI, instant results, 100% client-side. Health & Fitness Launch
⭐ Cholesterol Ratio & Risk Calculator Calculate Total/HDL, LDL/HDL, Non-HDL cholesterol, and AIP (atherogenic index). Private, client-side. Health & Fitness Launch
⭐ Child Growth Percentiles (CDC & WHO) Friendly growth percentiles using WHO (0–5y) and CDC (2–20y) LMS standards. Weight, length/height, BMI, head circumference. Private, client-side. Health Launch
⭐ Water Intake Calculator Estimate daily water needs using weight-based baselines with exercise, climate, altitude, and pregnancy/lactation adjustments. Private, client-side. Health & Wellness Launch
🎂 Birthday Countdown Live countdown to your next birthday with DOB dropdowns, leap-year handling, and shareable URL. Private, client-side. Time & Date Launch
⭐ Age Calculator Calculate age in years, months, and days, and find time until next birthday. Utility Tools Launch
⭐ Age in Weeks & Months Calculator See age in whole weeks + days, calendar months + days, and decimal months — baby-friendly and private. Utility Tools Launch
⭐ Age Difference Calculator Exact difference between two birthdays in years, months, and days, plus totals in days/weeks. Private, client-side. Time & Date Launch
🎂 Birthday Paradox Calculator Probability that at least two people share a birthday in a group; leap-day toggle, odds, and quick thresholds. Private, client-side. Calculators Launch
⭐ Browser Info Tool Show IP address, browser type, screen size, and user agent for tech support and debugging. Web Tools Launch
⭐ HTML Colour Picker Pick a colour from a palette and get its Hex, RGB, and HSL codes. Web Tools Launch
⭐ Markdown to HTML Converter Convert Markdown text to HTML instantly. Web Tools Launch
⭐ Base64 Encoder / Decoder Encode and decode text to and from Base64. Web Tools Launch
⭐ Image to Base64 Converter Convert any image to a Base64 string in your browser. Copy or download instantly. Web Tools Launch
⭐ Timestamp Converter Convert UNIX timestamps to human-readable dates and vice versa. Web Tools Launch
⭐ LDAP / FILETIME Converter Convert 18-digit LDAP/Windows FILETIME ↔ Date. Decimal & hex, UTC/local display, AD “Never” handled. Time & Date Launch
⭐ Apple Cocoa/Core Foundation Time Convert CFAbsoluteTime/NSTimeInterval (seconds since 2001-01-01 UTC) to dates and back — fractional seconds preserved. Time & Date Launch
⭐ Unix Hex Timestamp Converter Convert Unix timestamps in hex or decimal (seconds or milliseconds) to dates and back — auto-detect with override. Time & Date Launch
⭐ Mac HFS+ Timestamp Converter Convert HFS+ timestamps (seconds since 1904-01-01 UTC) to dates and back — hex/decimal input, optional byte-swap. Time & Date Launch
⭐ SAS Timestamp Converter Convert SAS datetime (seconds since 1960) or SAS date (days since 1960) ↔ human dates. Hex/decimal, fractional seconds. Time & Date Launch
⭐ JSON Formatter & Validator Pretty-print, minify, and validate JSON data instantly in your browser. Web Tools Launch
⭐ URL Encoder/Decoder Encode or decode special characters in URLs. Web Tools Launch
⭐ Hash Generator (MD5, SHA1, SHA256) Generate MD5, SHA1, and SHA256 cryptographic hashes of text strings. Web Tools Launch
⭐ Password Strength Checker Estimate strength, entropy & crack time with optional PBKDF2 timing — all client-side. Security Tools Launch
⭐ Blank Markdown Table Generator Visually create blank Markdown tables by selecting your desired rows and columns. Web Tools Launch
⭐ Regex Tester Test and build regular expressions against sample text with live highlighting. Web Tools Launch
⭐ Time Since/Until Calculator Calculate the duration (years, months, weeks, days, hours, minutes, seconds) since or until a specific date and time. Web Tools Launch
⭐ Time Zone Converter Convert a date & time across 2–3 time zones — DST-safe with 12/24-hour format, overlap suggestions, and a copyable link. Web Tools Launch
⭐ Printable Monthly Calendar Generate clean A4/Letter calendars with Monday/Sunday start, ISO week numbers, notes & mini-months. Print or save as PDF — 100% client-side. Time & Date Launch
⭐ ISO Week Number Converter Convert date ↔ ISO week/year and weekday (Mon–Sun), with full week range and 52/53-week validation. Fast, accurate, and 100% client-side for privacy. Time & Date Launch
⭐ Day-of-Year ⇄ Date & Weekday Converter Convert day-of-year (1–365/366) ↔ calendar date and instantly see the weekday. Leap-year aware, UTC-safe, and 100% client-side for privacy. Time & Date Launch
⭐ Holiday Countdown See days, hours, minutes, and seconds until popular fixed-date holidays (Christmas, Halloween, etc.). Includes a custom date countdown. Private, client-side. Time & Date Launch
⭐ Add/Subtract Business Days (+ Custom Holidays) Add or subtract business days with weekend toggles and custom holiday upload. Leap-year aware, UTC-safe, and 100% client-side for privacy. Time & Date Launch
⭐ Cron Expression Generator & Parser Generate or parse cron, view human-readable summaries, and preview next run times. Supports seconds/year and Quartz mode. Private, client-side. Time & Date Launch
⭐ Protein Isoelectric Point (pI) Calculator Estimate pI and net charge across pH using selectable pKa sets (EMBOSS, Bjellqvist) or custom overrides. 100% private—runs in your browser. Science & Research Launch
⭐ Meta Tag Generator Create SEO, Open Graph, and Twitter meta tags with live preview. Copy or download a ready-to-use head block. Web Tools Launch
⭐ Robots.txt Builder Build robots.txt with user-agent groups, Allow/Disallow rules, Sitemap URLs, and optional crawl-delay/Host. Copy or download. Web Tools Launch
⭐ CSS Gradient Generator Create linear or radial gradients with multiple color stops, live preview, and one-click CSS copy. Web Tools Launch
⭐ Scientific Figure & Page Extractor Extract high-quality images of figures and pages from research PDFs. Scientific Tools Launch
⭐ Research Abstract Formatter Format abstracts with IMRC headings, clean whitespace, and convert to HTML, Plain Text, or LaTeX. Scientific Tools Launch
⭐ BioStats Quick Calculator v0.9 Quickly calculate t-test, chi-square, or ANOVA for your biological data. Scientific Tools Launch
⭐ DNA/Protein Sequence Cleaner + Validator Clean and validate DNA/protein sequences, remove invalid characters, and ensure proper formatting. Scientific Tools Launch
⭐ Blot Image Cleaner Upload blot/gel images for auto-inversion, contrast enhancement, and noise removal. Scientific Tools Launch
⭐ PCR Primer Calculator (Tm & GC%) Compute primer Tm (Wallace, GC%, nearest-neighbor), GC%, GC clamp quality, and quick self-structure checks. Private, client-side. Science & Engineering Launch
⭐ Molarity Calculator Calculate mass, molecular weight, volume, or concentration for chemical solutions. Scientific Tools Launch
⭐ Molecular Weight Calculator Calculate molecular weight from chemical formulas or protein/DNA/RNA sequences. Scientific Tools Launch
⭐ Moles ↔ Mass ↔ Volume (Gas at STP) Convert between moles, grams, and gas volume using STP/IUPAC STP/SATP molar volume; can infer MW from mass + volume. Scientific Tools Launch
⭐ Lab Dilution Planner — Serial Dilutions Plan serial dilutions from stock to target with pipette limits, or build a fixed-fold ladder. Private, client-side. Science & Engineering Launch
⭐ Enzyme Kinetics Calculator Plot Michaelis–Menten and classic linearizations; fit Vmax & Km from your data. Private, client-side. Science & Engineering Launch
⭐ Protein Concentration Calculator Bradford & BCA standard curves and direct A280 (Beer–Lambert) with curve fitting, dilution, and path length. Private, client-side. Science & Research Launch
⭐ Beer–Lambert Law (A = εlc) Solve absorbance, molar absorptivity (ε), path length (l), or concentration (c). Includes %T ↔ A conversion and unit-aware inputs. 100% client-side. Scientific Tools Launch
⭐ Henderson–Hasselbalch — Buffer pH Compute pH from pKa and [A⁻]/[HA], or design a buffer recipe from target pH, total concentration, and volume. Unit-aware, with optional grams via molar masses. 100% client-side. Scientific Tools Launch
⭐ Dilution Calculator (C1V1=C2V2) v1.1 Calculate unknown concentrations or volumes using the C1V1=C2V2 formula. Scientific Tools Launch
⭐ Sample Size Calculator Determine the minimum sample size for comparative studies and A/B tests. Scientific Tools Launch
⭐ Triangle Calculator Solve any triangle by entering the three values that you know. Mathematics Tools Launch
⭐ Trigonometric Triangle Solver Solve any triangle (AAS, ASA, SAS, SSS, SSA) with Law of Sines/Cosines, degree/radian toggle, precision control, and ambiguous-case handling. Private, client-side. Calculators Launch
⭐ Heron’s Formula Calculator Triangle area from three sides using Heron’s formula, plus semiperimeter, inradius, circumradius, and altitudes. Private, client-side. Calculators Launch
⭐ Pythagorean Triples Generator Generate Pythagorean triples (a, b, c) with a²+b²=c². Primitive/all multiples, filters, live diagram, CSV export. Private, client-side. Math & Geometry Launch
⭐ Circle Calculator Compute radius, diameter, circumference, and area from any one value. Supports units, decimal places, and π precision. Mathematics Tools Launch
⭐ Ellipse Area & Perimeter Calculator Compute ellipse area (πab) and perimeter using Ramanujan I, Ramanujan II, and a high-precision elliptic-integral series. Works from a, b, A, B, area, or eccentricity. Private, client-side. Calculators Launch
⭐ Square Calculator Compute side, diagonal, perimeter, area, inradius, and circumradius from any one value. Units & decimal places. Private, client-side. Calculators Launch
⭐ Rectangle Calculator Compute width, height, diagonal, perimeter, area, and circumradius from any two values. Units & decimals. Private, client-side. Calculators Launch
⭐ Trapezoid Calculator Enter bases, legs, or height to get area, perimeter, diagonals & midline. General / isosceles / right. Private, client-side. Math & Geometry Launch
🧊 Cube Calculator Compute edge length, surface area, volume, and space diagonal from any one value. Private, client-side. Calculators Launch
🛢️ Cylinder Calculator Compute radius/diameter, height, surface area, lateral area, and volume from any two values. Private, client-side. Calculators Launch
🎯 Cone Calculator Compute radius/diameter, height, slant height, surface area, lateral area, and volume from any two values. Private, client-side. Calculators Launch
🌐 Sphere Calculator Compute radius/diameter, surface area, and volume from any one value. Choose units, decimals, and π precision. Private, client-side. Calculators Launch
⭐ Pyramid Calculator Surface area, volume, height, and slant height for regular pyramids. Private, client-side. Calculators Launch
⭐ Regular Polygon Calculator Area, perimeter, side/apothem, circumradius, and angles for an n-gon. Private, client-side. Calculators Launch
⭐ Irregular Polygon Area Calculator Compute area (shoelace), perimeter, centroid, and orientation from vertex coordinates. Private, client-side. Calculators Launch
⭐ Polygon Interior/Exterior Angles Calculator Compute per-vertex interior and signed exterior angles, plus sums and orientation. Regular or custom coordinates. Private, client-side. Calculators Launch
⭐ Conic Equation Finder Compute equations for circles, parabolas, ellipses, and hyperbolas from points, foci, directrix, or parameters. Private, client-side. Math & Geometry Launch
⭐ Quadratic Equation Calculator Solve quadratic equations (ax² + bx + c = 0) and see the step-by-step solution. Mathematics Tools Launch
⭐ Ratio Calculator Solve for a missing ratio value and visualize the relationship. Mathematics Tools Launch
⭐ Fraction Calculator Add, subtract, multiply, and divide fractions & mixed numbers with step-by-step simplification. Mathematics Tools Launch
⭐ Proportion Calculator Solve proportions step by step — find the missing value in “a is to b as c is to ?”. Mathematics Tools Launch
⭐ Percentage Calculator Find the percentage of a number, determine percentages, and more. Calculator Tools Launch
⭐ Percentage Change Calculator Quantify the increase or decrease between two values. Calculator Tools Launch
⭐ Mean, Median, Mode Calculator Calculate the mean, median, mode, range, and other key statistics for a set of numbers. Calculator Tools Launch
⭐ Average (Mean) Calculator Quickly compute the arithmetic mean of numbers with support for spaces, commas, and new lines. Calculator Tools Launch
⭐ Standard Deviation & Z-Score Calculator Paste numbers to get mean, variance, standard deviation (population/sample), and per-value z-scores — all client-side. Calculator Tools Launch
⭐ Binomial & Poisson Calculator Enter n,p,k (or λ,k) to compute PMF, CDF, expected value, variance, and view a probability bar chart — all client-side. Calculator Tools Launch
⭐ Exponent / Power Calculator (xy) Calculate powers like 25 or 10-3 in a kid-friendly xy layout. Supports negatives, zero exponents, and scientific notation. Calculator Tools Launch
⭐ Prime Factorization Calculator Check if a number is prime and get its full prime factorization with exponents — instant, private, and student-friendly. Calculator Tools Launch
⭐ Scientific Notation Converter Convert standard ↔ scientific (a × 10n) & engineering notation. Handles E-notation and significant figures — 100% client-side. Calculator Tools Launch
⭐ Logarithm Calculator Compute ln, log10, log2, and log base b; includes change-of-base and antilog — 100% client-side. Calculator Tools Launch
⭐ Permutation & Combination Calculator Compute permutations (nPr) and combinations (nCr) — with or without repetition, exact BigInt results plus approximation. Calculator Tools Launch
⭐ LCM & GCF Calculator Find least common multiple (LCM) and greatest common factor (GCF/HCF) of any integers — supports negatives, zero, and BigInt for large values. Calculator Tools Launch
⭐ APR ↔ APY Converter & CAGR Convert APR⇄APY with custom, daily (360/365), and continuous compounding, plus calculate CAGR instantly. Calculator Tools Launch
⭐ NPV & IRR Calculator Compute NPV & IRR from a cash-flow table; switch between equal periods or exact dates (XNPV/XIRR), with CSV import/export — 100% client-side. Calculator Tools Launch
⭐ Perpetuity Calculator Compute present value (PV) for level, due, or growing perpetuities — or solve for cash flow (C), discount rate (r), or growth (g). 100% client-side. Calculator Tools Launch
⭐ Mortgage Repayment Calculator Estimate loan payments, total interest, and view a full amortization schedule. Calculator Tools Launch
⭐ Mortgage vs Renting Calculator Compare buying vs renting over time—monthly costs, equity, and cumulative net cost with a simple chart. Calculator Tools Launch
⭐ Loan Calculator Calculate monthly payments and view a full repayment schedule. Calculator Tools Launch
⭐ Loan Comparison Compare two loans side by side, add extra payments, and see early payoff savings. Calculator Tools Launch
⭐ Auto Loan Calculator Estimate car payments with down payment, trade-in, taxes, fees, APR, and term. Includes amortization schedule. Calculator Tools Launch
⭐ Debt Snowball & Avalanche Calculator Prioritize debts via Snowball or Avalanche, apply extra budget, and see payoff dates, total interest, and a month-by-month schedule. Private, client-side. Finance & Money Launch
⭐ Debt Avalanche Calculator Prioritize highest APR balances to minimize interest. Enter debts, add extra budget, and view your payoff schedule. Private, client-side. Finance & Money Launch
⭐ Minimum Credit Card Payment Calculator Estimate minimum payment, payoff time, and total interest. Supports “% of balance” or “greater of %/fixed”. Private, client-side. Personal Finance Launch
⭐ Debt Consolidation Calculator See if a consolidation loan could lower your monthly payment or total interest. Compare APR, term, and fees vs. current debts. Private, client-side. Personal Finance Launch
⭐ Debt-to-Income (DTI) Ratio Calculator Calculate housing (front-end) and total (back-end) DTI with monthly or annual income. Includes friendly thresholds and guidance. Private, client-side. Personal Finance Launch
⭐ Loan Affordability Calculator Estimate maximum affordable payment, loan amount, and (in mortgage mode) home price from income, debts, and DTI caps. Private, client-side. Personal Finance Launch
⭐ Refinance Break-Even Calculator Compare old vs new payment, costs & points, and see months to break even plus interest over your hold period. Private, client-side. Finance & Mortgages Launch
⭐ Credit Card Payoff Time Calculator Project months to payoff from a fixed payment, estimate total interest, and export an amortization table. Private, client-side. Finance & Money Launch
⭐ New vs Old Car Cost Calculator Compare total cost of ownership: purchase/financing, fuel or electricity, maintenance, insurance, fees, and resale. Shows NPV, EAC, and cost per mile. Calculator Tools Launch
⭐ Car Insurance Cost Estimator Estimate an illustrative annual premium with a clear factor breakdown. Currency & tax settings, CSV export. Private, client-side (not a quote). Calculator Tools Launch
⭐ Life Insurance Calculator Educational level-term premium estimator using survival probabilities & present-value math. Shows net & illustrative gross premiums, death-in-term probability, and CSV export. Private, client-side (not a quote). Calculator Tools Launch
⭐ Health Insurance Cost Estimator Educational tool that estimates your total annual cost: premiums + out-of-pocket under deductible, copays, coinsurance, and OOP maximum. Clear line-by-line breakdown, flow-through visualization, scenario presets, and CSV export. Private, client-side (not a quote). Calculator Tools Launch
⭐ Dental Insurance Cost Estimator Educational tool that estimates your annual dental cost: premiums + your share after deductible and class coinsurance, with plan-side caps (annual max) and orthodontic lifetime max. Shows Preventive/Basic/Major/Ortho breakdown, waiting-period toggles, clear table outputs, and CSV export. Private, client-side (not a quote). Calculator Tools Launch
⭐ Travel Insurance Cost Estimator Educational single-trip premium estimator with transparent factors: duration, destination region, age, medical limit, excess, sports/activities, baggage, and cancellation. Shows clear breakdown, risk multiplier, presets, and CSV export. Private, client-side (not a quote). Calculator Tools Launch
⭐ Business Insurance Calculator Transparent, educational estimator for GL, Property, Workers’ Comp, and Professional/Cyber. Exposure × base rate with clear factor breakdown (limits, deductibles, territory, experience), minimum premium/fees, taxes, and CSV export. Private, client-side (not a quote). Calculator Tools Launch
🏠 House Insurance Cost Estimator Transparent, educational estimator for Buildings & Contents with clear multipliers (rebuild cost, contents, construction, roof age, security, flood/wind/crime, occupancy, claims), optional endorsements, excess/deductible effects, taxes, and CSV export. Private, client-side (not a quote). Calculator Tools Launch
🏢 Apartment / Flat Insurance Estimator Estimate an illustrative annual premium with a transparent factor breakdown (contents, floor level, sprinklers, security, location, excess). Currency & tax settings, CSV export. Private, client-side (not a quote). Calculator Tools Launch
🧳 Renters Insurance Cost Estimator Educational HO-4/tenant tool estimating an illustrative annual premium with a transparent factor breakdown (contents limit, building type, floor level, security & crime, deductible, liability, endorsements/discounts). Currency & tax settings, CSV export. Private, client-side (not a quote). Calculator Tools Launch
🐾 Pet Insurance Cost Estimator Estimate an illustrative monthly & annual premium with a transparent factor breakdown (species, breed risk, age, weight, vet-cost index, limit, reimbursement, deductible). CSV export. Private, client-side (not a quote). Calculator Tools Launch
⭐ Bitcoin Unit Converter Instantly convert BTC ↔ satoshi ↔ mBTC ↔ μBTC. Privacy-first, client-side math. Finance & Crypto Launch
⭐ Mining Profitability Calculator Estimate revenue, electricity cost, profit, and ROI from hashrate, power, price/kWh, difficulty, and block reward. Private, client-side. Finance & Crypto Launch
⭐ Crypto Profit/Loss Calculator Compute absolute P/L, ROI %, breakeven sell price, and fee breakdown from buy/sell price, quantity, and fees. Private, client-side. Finance & Crypto Launch
⭐ Crypto DCA Calculator Plan dollar-cost averaging with recurring amount, frequency, fees, and prices. Shows total invested, total units, average cost basis, and unrealized P/L. Private, client-side. Finance & Crypto Launch
⭐ Amortization Calculator Calculate fixed loan payments, total interest, and generate an amortization schedule. Supports multiple currencies and flexible terms (days, months, years). Calculator Tools Launch
⭐ Payback Time Calculator Measure how long it takes to recover an investment with simple and discounted payback. Supports annual/monthly periods, constant or custom cash flows, CSV export, and a cumulative chart. Calculator Tools Launch
⭐ VAT & Sales Tax Calculator Add or remove VAT (UK/EU) or sales tax (US). Choose standard, reduced, or zero rates—or override with your own value. Fully client-side for privacy. Calculator Tools Launch
⭐ Annuity PV/FV & Break-Even Compute PV/FV for ordinary/due and growing annuities, plus break-even units & revenue, margin, and markup — with annual→per-period rate conversion. 100% client-side. Calculator Tools Launch
⭐ Discrete Compounding Calculator PV/FV for lump sums & ordinary/due annuities, solve for rate or periods, plus APR↔EAR and periodic-rate helpers — 100% client-side. Calculator Tools Launch
⭐ Simple Interest Calculator Calculate simple interest and the total amount instantly. Calculators Launch
⭐ Simple vs Compound Interest Compare simple vs compound interest side-by-side — totals, EAR, and a clean growth chart. Calculators Launch
⭐ ROI Calculator Calculate Return on Investment (ROI) and annualized returns. Calculators Launch
⭐ ROI by Project / Business Line Calculator Multi-project ROI with per-row fees, dates or duration, CAGR, and portfolio weighted ROI. 100% client-side. Finance & Accounting Launch
⭐ Rule of 72 Calculator Estimate doubling time or required annual rate with the Rule of 72 and see the exact compounding comparison. Private, client-side. Finance & Investing Launch
⭐ Tip Calculator Quickly calculate tips, split bills, include/exclude tax, and apply rounding. Calculators Launch
⭐ Restaurant Bill Splitter & Tip Calculator Enter meals, prices, and quantities to split a restaurant check evenly. Add a tip by percent or fixed amount—mobile-friendly and private. Calculators Launch
⭐ Shipping Cost Calculator — FOB vs CFR Compute CIF, duty, VAT, insurance (110% uplift), destination fees, FX conversion, and per-unit landed cost—simple, client-side. Calculators Launch
⭐ SIP Calculator Estimate total invested, wealth gained, and maturity value for systematic investments. Calculators Launch
⭐ CD Calculator Calculate maturity value and interest earned from fixed-term deposits with APY/APR and compounding. Calculators Launch
⭐ Discount Rates Calculator Compare single vs. stacked discounts, compute the equivalent rate, and reverse-calc a target price — with optional sales tax. Calculators Launch
⭐ Markup & Margin Calculator Convert markup ↔ margin, price from cost, profit per unit, and compare scenarios — optional tax display. Calculators Launch
⭐ ARR Calculator Compute Accounting Rate of Return from average profit using initial or average investment, with simple or detailed mode (depreciation & tax). Calculators Launch
⭐ One Rep Max Calculator Estimate your one-repetition max using Epley, Brzycki, and Lombardi formulas. Calculators Launch
⭐ Race Split Planner Plan even or negative splits for 5K/10K/Half/Marathon with per-km/mi targets and CSV export. Calculators Launch
⭐ Pace / Speed / Time Enter any two (pace, speed, time, or distance) and compute the third — km/mi aware with instant conversions and CSV export. Calculators Launch
⭐ AOE Calculator Convert between your local time and AOE (UTC−12). Shows offset difference & day shift. DST-safe and fully client-side. Time & Date Launch
⭐ Date Calculator Find days between dates (incl. business days) or add/subtract days, weeks, months, or years. Calculators Launch
⭐ Workdays Calculator Count workdays between two dates or add/subtract business days — optional holidays supported. Time & Date Launch
⭐ All-in-One Unit Converter Convert length, mass, temperature, area, volume, speed, time, and digital storage — fully client-side for privacy. Calculators Launch
⭐ Binary/Hex/Octal Converter Convert between binary, octal, decimal, and hex — supports negatives, BigInt, prefixes, and 4-bit grouping. 100% client-side for privacy. Calculators Launch
⭐ HTML Minifier & Beautifier Minify HTML for smaller size or beautify for readability — all processed locally in your browser for privacy. Web Development Tools Launch
⭐ JavaScript Minifier & Beautifier Minify JavaScript for faster load times or beautify for readability — fully client-side for privacy. Web Development Tools Launch
⭐ YAML to JSON Converter Convert YAML to JSON instantly in your browser — 100% client-side for privacy and speed. Web Development Tools Launch
⭐ JWT Encoder Build and sign JWTs (none, HS256, RS256) with easy time-claim helpers. Private, client-side. Web Dev Launch
⭐ JWT Decoder Decode JWTs, view header/payload, check exp/nbf/iat, and verify HS256/RS256 signatures. Private, client-side. Web Dev Launch
⭐ Lorem Ipsum Generator Generate Lorem Ipsum filler text by words, sentences, or paragraphs. Copy as plain, HTML, or Markdown — all client-side. Web Development Tools Launch
⭐ Stopwatch Accurate stopwatch with laps, keyboard shortcuts, and CSV export — 100% client-side for privacy. Time & Date Tools Launch
⭐ Sleep Calculator Find the best bedtimes or wake-up times using 90-minute sleep cycles and a fall-asleep buffer — all client-side for privacy. Time & Date Tools Launch
⭐ Countdown Timer Set hours, minutes, and seconds, then run a smooth countdown with live milliseconds. Presets, Start/Pause/Reset, optional chime — all client-side. Time & Date Tools Launch
⭐ Pomodoro Timer Run calm focus/break cycles with session stats, streaks, chime, and desktop notifications. Private, client-side. Time & Date Launch
⭐ Beam Load Calculator Compute support reactions, shear force, and bending moment diagrams for simply supported beams with point loads and UDLs. Science & Engineering Launch
⭐ Engineering Tolerances Calculator Hole & shaft limits, min/max clearance or interference, and fit classification from deviations or IT grades (H/h/js). Private, client-side. Science & Engineering Launch
⭐ Fluid Flow Calculator Calculate Reynolds number, velocity, and pipe diameter. Classify flow regime as laminar, transitional, or turbulent. Science & Engineering Launch
⭐ Buoyancy Calculator Buoyant force and floating depth (draft) from ρ, V, g. Optional Awp and mass/weight for equilibrium draft. Private, client-side. Science & Engineering Launch
⭐ RC Time Constant Calculator Compute τ = R·C and plot charging & discharging curves from an initial voltage. Unit-aware inputs. Private, client-side. Science & Engineering Launch
⭐ Work, Power & Energy Calculator Compute work from force, displacement & angle, average power from time, and efficiency from input energy/power. Private, client-side. Science & Engineering Launch
⭐ Gravity & Newton’s Second Law Calculate surface/altitude gravity (g), Earth-g, and weight; solve F = m·a. Presets for Solar System bodies or custom mass/radius. 100% client-side. Science & Engineering Launch
⭐ Free Fall & Gravity Calculator Compute time to hit ground, impact velocity, and kinetic energy from height. Presets for Earth, Moon, Mars, Jupiter; optional initial velocity & mass. 100% client-side. Science & Engineering Launch
⭐ Acceleration Unit Converter Convert m/s², g, ft/s², in/s², Gal/mGal/µGal, km/h/s, mph/s, and knot/s with adjustable precision, fixed/scientific notation, and one-click copy & share — all client-side. Science & Engineering Launch
⭐ Projectile Motion Calculator Compute range, time of flight, maximum height, apex distance & impact speed — presets for Earth/Moon/Mars, custom g, initial height, and speed in m/s, km/h, or mph. 100% client-side. Science & Engineering Launch
⭐ Centripetal Force Calculator Compute centripetal force, radial acceleration, and g-forces from mass, speed, and radius. Private, client-side. Science & Engineering Launch
⭐ Kinetic & Potential Energy Calculator Compute KE (½mv²), PE (mgh), total mechanical energy, and use conservation to find speed at a height or max height. Private, client-side. Science & Engineering Launch
⭐ Spring Oscillator Calculator Hooke’s Law force, SHM period/frequency (T, f, ω), and max potential energy from k, m, and x. Private, client-side. Science & Engineering Launch
⭐ Resonance & Natural Frequency Calculator Mass–spring–damper & RLC (series/parallel) resonance: ωₙ / fₙ, ζ, Q, α, damped frequency, and bandwidth. Private, client-side. Science & Engineering Launch
⭐ Lens / Mirror Equation Calculator Thin lens & spherical mirror calculator for image distance, magnification, and image nature. Private, client-side. Science & Engineering Launch
⭐ Ideal Gas Law Calculator (PV = nRT) Solve for P, V, n, or T with friendly units and STP/SATP presets. Includes Boyle’s, Charles’s, and Gay-Lussac two-state calculators. Private, client-side. Science & Engineering Launch
⭐ Torque & Moment of Inertia Calculator Torque from force & lever arm; I for solid sphere, cylinder/disk, or thin rod; angular acceleration and rotational KE. Private, client-side. Science & Engineering Launch
⭐ Star Field Planetarium (In Development) Explore a realistic 3D starry night sky with interactive controls. Cosmology Launch
⭐ Redshift to Distance Calculator Calculate Luminosity, Angular Diameter, and Comoving Distances from Redshift. Cosmology Launch
⭐ Space Unit Converter Instantly convert between Astronomical Units (AU), Light-Years (ly), Parsecs (pc), and Kilometers (km). Cosmology Launch
⭐ Cosmology Calculator (Age & Distance) Calculate the age of the universe and cosmic distances for a given redshift. Cosmology Launch
⭐ Rocket Delta-V Calculator Compute rocket Δv with up to 4 stages using the Tsiolkovsky equation — per-stage and total results with chart. Science Launch
⭐ Satellite Orbit Period Calculator Enter altitude to calculate orbital period, orbital velocity, and revolutions per day using Kepler’s Third Law. Science Launch
⭐ Hohmann Transfer Calculator Compute Δv₁, Δv₂, total Δv, and transfer time between circular orbits. Optional plane-change combination. Science Launch
⭐ Conway’s Game of Life Interactive pixel-grid simulator of Conway’s Game of Life — draw, run, pause, and explore emergent patterns. Science Launch
⭐ Ant Colony Simulator Interactive simulation of ant foraging behavior — watch pheromone trails emerge and tweak evaporation, diffusion, and agent count. Science Launch
⭐ Population Growth Simulator Exponential vs logistic growth with adjustable N₀, r, K, Δt, and noise. Live chart, stats, and export. Private, client-side. Science & Engineering Launch
⭐ Markov Chain Random Walk Build a transition matrix and simulate random walks. Path preview, visit statistics, CSV/JSON export. Private, client-side. Science & Engineering Launch
⭐ Escape Velocity Calculator Compute escape velocity at any altitude and see circular speed (v_circ) with the √2 relationship. Supports Earth, Moon, Mars, or custom body. Private, client-side. Science & Engineering Launch
⭐ Blackbody Radiation Calculator Compute peak wavelength via Wien’s law and radiated power via Stefan–Boltzmann; optional emissivity & area; client-side and private. Science & Engineering Launch
⭐ COSMOTOOLS — Modern Cosmology Calculator Luminosity, comoving & angular distances, lookback time, age, q0 & Ωk with adjustable H0, ΩM, ΩΛ. Private, client-side. Science & Research Launch
⭐ Compound Interest Calculator Project your financial growth with contributions and inflation adjustment. Calculators Launch
⭐ Compound Interest Table Generator Generate tables across rates (0.25%–100%) with custom step, EAR/APR conversion, CSV export, and an interactive graph. Calculators Launch
⭐ Salary to Hourly Converter Convert annual salaries to hourly wages and vice versa, with after-tax estimation. Calculators Launch
⭐ Hourly → Annual Salary Calculator Convert hourly wages into weekly, monthly, and annual salaries with optional after-tax estimate. Calculators Launch
⭐ Net Income Calculator Compute Net Income and NOPAT from EBIT/EBT or a full operating layout; shows EBITDA, EBT, taxes, and margins — 100% client-side. Calculators Launch
⭐ EBIT & EBITDA Calculator Calculate EBITDA and EBIT from revenue/costs or direct inputs. Includes D&A, other operating, and profit margins. Private, client-side. Finance & Accounting Launch
⭐ Savings Goal / Sinking Fund Set a target and plan by date or monthly budget — includes progress bar, live chart, and CSV schedule. Calculators Launch
⭐ Savings vs. Investing Comparison Side-by-side cash vs. investing with breakeven timing, “today’s money,” optional uncertainty band, and downloadable CSV. Private, client-side. Calculators Launch
⭐ Inflation-Adjusted Return (Real Return) Calculator Real return from nominal & inflation (Fisher), real CAGR from CPI, plus required nominal for a target real. Private, client-side. Calculators Launch
⭐ Retirement Withdrawal / 4% Rule Simulator Classic 4% rule with inflation indexing, flat £ withdrawals, or % of portfolio. Monthly compounding, COLA, live chart, and depletion check. Private, client-side. Calculators Launch
⭐ Rebalancing Impact Calculator See how periodic or threshold rebalancing compares to Buy & Hold—CAGR, volatility, drawdowns, turnover, and trading costs. Private, client-side. Calculators Launch
⭐ Investment Goal Tracker Plan an investment goal by date or budget with return, fees, inflation, and optional volatility. Live chart, success probability, CSV. Private, client-side. Calculators & Finance Launch
⭐ Dividend Reinvestment (DRIP) Calculator Simulate dividend reinvestment with yield or DPS, dividend & price growth, tax rate, frequency, and monthly contributions. Fractional shares, live chart, CSV. Private, client-side. Calculators & Finance Launch
⭐ Time-Weighted Return (TWR) Calculator Compute TWR by linking subperiod returns or via Modified Dietz when flows occur within periods. Growth chart, CAGR, CSV. Private, client-side. Calculators & Finance Launch
💼 Portfolio Return (Weighted Average ROI) Calculator Compute per-holding ROI plus invested-weighted and value-weighted portfolio returns. Add fees & income, optional date range for CAGR. Private, client-side. Finance & Investing Launch
⭐ Budget Planner — 50/30/20 Rule Build a monthly budget with Needs/Wants/Saving targets, live totals, progress bars, and a donut chart. Private, client-side. Finance & Budgeting Launch
⭐ Emergency Fund Calculator Estimate your target emergency fund from essential expenses, see current coverage and time-to-goal, with a projection chart. Private, client-side. Finance & Budgeting Launch
⭐ Retirement Planner Plan for retirement with sliders for savings, age, returns, and inflation — includes live growth chart. Calculators Launch
⭐ FIRE Calculator Calculate your FI number and projected date using SWR, contributions, returns, and inflation—complete with a live growth chart. Private, client-side. Finance & Budgeting Launch
⭐ Salary to Hourly Converter Convert annual salaries to hourly wages and vice versa, with after-tax estimation. Calculators Launch
⭐ Inflation Calculator Adjust money across years using CPI, compute Fisher inflation and forward rates — all client-side. Calculators Launch
⭐ PPP Calculator — Purchasing Power Parity Convert amounts with PPP conversion factors or CPI + FX; privacy-first, 100% client-side. Finance & Economics Launch
💱 Interest Rate Parity Calculator Price FX forwards with covered IRP, solve implied rates from spot/forward, or estimate expected spot via UIP. Private, client-side. Finance & Economics Launch
📈 Real GDP Growth Adjustment Calculator Convert nominal GDP growth to real using inflation (Fisher), compute real growth from levels + deflators, and chain multi-period real growth. Private, client-side. Finance & Economics Launch
💷 Inflation Impact on Salary Compute real raises vs inflation, break-even raises, CPI-based adjustments between dates, and chain multi-year purchasing power. Private, client-side. Finance & Economics Launch
🌍 Exchange Rate Impact on Investments Unhedged vs hedged returns, FX decomposition, scenarios, and break-even FX—private, client-side. Finance & Economics Launch
⭐ Cash Conversion Cycle (CCC) Calculator Compute DIO, DSO, DPO, and overall CCC days. Includes turnovers, date or length mode. 100% client-side. Finance & Accounting Launch
⭐ Bond Calculator v1.1 A simple financial tool to calculate a bond's price, yield, coupon, or maturity. Calculators Launch
⭐ Stock Return Calculator CAGR and total return with dividends; DRIP option, dividend tax, equity curve, and cash-flow CSV. Private, client-side. Finance Launch
⭐ Temperature Converter Convert between Celsius, Fahrenheit, Kelvin, Rankine, and Réaumur. Calculators Launch
⭐ 2D Distance Calculator Calculate the distance between two points (x1, y1) and (x2, y2) on a 2D plane. Calculators Launch
⭐ 3D Distance Calculator Calculate the distance between two points (x1, y1, z1) and (x2, y2, z2). Calculators Launch
⭐ Midpoint Calculator (2D & 3D) Compute the midpoint between two points in 2D or 3D with an isometric preview. Private, client-side. Math & Geometry Launch
⭐ Line Intersection Calculator Solve for the intersection of two linear equations (Ax+By=C or y=mx+b). Flags parallel or coincident lines. Private, client-side. Math & Geometry Launch
⭐ Vector Projection / Dot & Cross Product Compute dot, cross (3D), projection of a onto b, angle, magnitudes, and parallel/perpendicular components. 2D & 3D. Private, client-side. Calculators Launch
⭐ Coordinate Transformations (2D) Translate, rotate (about origin or a point), reflect (axes, y=x, y=−x, angle), and scale (uniform/non-uniform) with live preview. Private, client-side. Calculators Launch
⭐ Slope Calculator Compute slope m, angle, and line equations (y=mx+b, point–slope, Ax+By=C) between two points. Handles vertical lines. Private, client-side. Calculators · Geometry Launch
⭐ Vector Component Resolver (2D/3D) Compute x/y(/z) components, |a|, unit vector, projection of a onto b, and rejection. Supports component or magnitude+angles input. Private, client-side. Calculators · Vector Math Launch
📐 Angle Between Two Vectors 2D & 3D vector angle (deg/rad), cosine similarity, dot product, magnitudes. Private, client-side. Calculators Launch
⭐ Rotation Matrix Calculator (2D) Build the 2×2 rotation matrix R(θ) and rotate points CW/CCW about the origin or any center. Paste a list for batch rotation. Private, client-side. Calculators Launch
⭐ Point to Line Distance (2D) Perpendicular distance from a point to a line in Ax+By+C=0, y=mx+b, or via two points. Private, client-side. Math & Geometry Launch
⭐ Point to Plane Distance (3D) Perpendicular distance from a 3D point to a plane. Supports Ax+By+Cz+D=0, point+normal, or three points; shows foot and signed/unsigned distance. Private, client-side. Science & Engineering Launch
⭐ Plane from 3 Points Compute a plane from three points or point+normal; outputs Ax+By+Cz+D=0, unit-normal form, and point–normal form. Private, client-side. Science & Engineering Launch
⭐ Golden Ratio Calculator Compute golden sections a, b, and L using φ with a live golden-rectangle preview. Private, client-side. Math & Geometry Launch
⭐ Tire Size Calculator Compare two tire sizes by sidewall, diameter, circumference, revs per mile/km, ride height, and speedometer error. Calculators Launch
⭐ IP Subnet Calculator Enter IPv4 or IPv6 CIDR to instantly see network address, range, usable hosts, and total addresses — all calculated client-side. Calculators Launch
⭐ Ohm’s Law Calculator Enter any two values (Voltage, Current, Resistance, Power) to instantly calculate the other two — with unit scaling and step-by-step formulas. 100% client-side. Science & Engineering Launch
⭐ AC Power Calculator Calculate real (P), apparent (S), and reactive (Q) power from voltage, current, and power factor or angle — supports single-phase and three-phase. 100% client-side. Science & Engineering Launch
⭐ DC Power Calculator Compute direct current power with P = V × I — enter any two values (Voltage, Current, Resistance, Power) to instantly find the others. 100% client-side. Science & Engineering Launch
⭐ dB / dBm / Watt Converter Convert between dB, dBm, dBW, and Watts — with optional Vrms/Vpp/Irms from a chosen impedance (e.g., 50 Ω). Enter one value, get the rest. 100% client-side. Science & Engineering Launch
⭐ Wavelength ↔ Frequency Calculator Convert between wavelength (λ) and frequency (f) using λ = c/(n·f) with medium presets (vacuum, air, water, glass) or custom refractive index. Also shows period, wavenumber, and photon energy. 100% client-side. Science & Engineering Launch
⭐ Voltage Divider Calculator Enter any three of Vin, Vout, R1, and R2 to solve the fourth. Includes optional load (RL) simulation, divider current, and resistor power — 100% client-side. Science & Engineering Launch
⭐ UPS Runtime & Sizing Calculator Estimate UPS runtime from load and battery specs, or size a UPS for your equipment — includes VA ↔ W conversion and efficiency. 100% client-side. Science & Engineering Launch
⭐ RAID Calculator Estimate usable capacity, redundancy overhead, efficiency, and fault tolerance for RAID 0, 1, 5, 6, 10, 50 & 60 — 100% client-side. Science & Engineering Launch
⭐ Paint, Flooring & Tile Coverage Calculator Calculate paint litres and tins, flooring area and packs, plus tile counts and boxes. Multiple rooms, coats & waste. Private, client-side. Calculators Launch
⭐ Packing Volume Calculator Estimate boxes for moving & shipping from item dimensions and quantities. Packing efficiency, fragile padding, weights, and printable summary. Private, client-side. Calculators Launch
⭐ Fabric Yardage Calculator Estimate yardage/metreage with fabric width, seam/hem allowances, nap, vertical repeat, shrinkage, and store rounding. Private, client-side. Calculators Launch
⭐ Concrete Yardage Calculator Slabs, footings, sonotubes/post holes. Imperial/metric, waste %, and bag counts. Private, client-side. Calculators Launch
⭐ HVAC BTU Calculator Estimate room cooling & heating loads, convert to AC tons, and apply sun/insulation/occupancy adjustments. Private, client-side. Calculators Launch
⭐ Acoustic Impedance Calculator z=ρc (Rayl), tube impedance Zc=ρc/S, wavelength, and interface reflection/transmission at normal incidence. Client-side. Science & Engineering Launch
⭐ Air — Speed of Sound vs. Temperature Compute speed of sound from temperature with optional RH & pressure. Linear approximation + moist-air model. Client-side. Science & Engineering Launch
⭐ Gases – Speed of Sound Quick reference: sound speed in gases with search, unit switching, and √T temperature normalization. Private, client-side. Science & Engineering Launch
⭐ Fans — Noise Power Generation Empirical overall sound power level from S, Q, p. SI & Imperial inputs. Client-side. Science & Engineering Launch
⭐ Floor Vibrations — Resonance Check Compute first-mode frequency for joist floors or slabs and check resonance risk vs. human activity & machinery. Private, client-side. Science & Engineering Launch
⭐ Random Number Generator Generate a random number within a custom range and with a specific number of decimal points. Random Tools Launch
⭐ Number Set Generator Generate integer or decimal sets — unique or with repeats, optional step/grid, sorting, and export. Random Tools Launch
⭐ Random Choice Generator Randomly pick a choice from a list of options. Random Tools Launch
⭐ Random letter Generator Generate a single random letter from the alphabet. Random Tools Launch
⭐ Random date Generator Generate one or more random dates within a specified range. Random Tools Launch
⭐ Random IP Address Generator Generate random IPv4 addresses with options to exclude private and broadcast ranges. Random Tools Launch
⭐ Random MAC Address Generator Generate random MAC (EUI-48) addresses with format & case options, unicast/multicast and U/L bit control, plus optional vendor OUI seeding. Random Tools Launch
⭐ List Randomizer Shuffle a list of items, names, or any text into a random order. Random Tools Launch
⭐ Strong Password Generator Generate a secure, random password with customizable length and character sets. Random Tools Launch
🎲 UUID v1 Generator Generate time-based UUID v1 (RFC 4122) with clock sequence and node. Batch 1–200, multiple formats, copy/download. Private, client-side. Random & Lists Launch
🎲 UUID v3 Generator Create deterministic UUID v3 (MD5) from a namespace and name. Built-in DNS/URL/OID/X.500 or custom, batch 1–200, multiple formats. Private, client-side. Random & Lists Launch
⭐ UUID v4 Generator Generate one or many RFC 4122 compliant UUIDv4 identifiers with color-coded parts. Random Tools Launch
🎲 UUID v5 Generator Create deterministic UUID v5 (SHA-1) from a namespace and name. Built-in DNS/URL/OID/X.500 or custom, batch 1–200, multiple formats. Private, client-side. Random & Lists Launch
⭐ Dice Roller Rolls a customizable number of d6 dice with a visual display and total sum. Random Tools Launch
⭐ Coin Flipper A simple tool to flip a coin for a heads or tails decision. Random Tools Launch
⭐ Bingo Card Generator Create and print unique, random 5x5 bingo cards with a free space. Random Tools Launch
🧩 Printable Sudoku Generator Generate printable 9×9 Sudoku puzzles (Easy/Medium/Hard). Save as PNG/PDF or print — fully client-side. Random Tools Launch
🌀 Random Maze Generator Generate printable mazes with custom size & cell width, entrance/exit options, solution overlay, and braid (loops). Save as PNG/PDF or print — fully client-side. Random Tools Launch
✨ Kaleidoscope Pattern Soothing, seedable kaleidoscope with gentle rotation. Choose slices, palette, speed & breathing; switch to Draw mode for mirrored strokes with per-stroke colours. Mobile-friendly and 100% client-side. Random Tools Launch
🎡 Spin the Wheel — Random Picker Paste options and spin to pick a fair random winner. Private, client-side; optional no-repeat draws and copyable history. Random & Lists Launch
⭐ Random Astronomy Sky Map Generator Generate a seeded star chart with adjustable star count, brightness curve, optional RA/Dec grid, and PNG export. Private, client-side. Science & Astronomy Launch
⭐ Random Color Palette Generator Generate harmonizing color palettes for your designs and lock in colors you like. Random Tools Launch
🎮 Tic Tac Toe Classic 3×3 Tic Tac Toe game — play vs friend or computer (Easy, Normal, Unbeatable), choose X/O, track scores. Games Launch
🎲 2048 Game Play the classic 4×4 2048 puzzle — slide tiles, merge numbers, use Undo, and aim for 2048. Smooth, mobile-friendly, ad-light. Games Launch
🧩 Sudoku Play Sudoku — Easy/Medium/Hard with notes, hints, undo, timer, and error highlighting. Mobile-first and privacy-friendly. Games Launch
🧠 Mental Math Trainer Practice percentages, fractions, and squares — play Practice or 60/120s speed rounds with gentle feedback, skip, and local bests. Keyboard-friendly and private. Games Launch
🍕 Fraction Pizza Visualize fractions—choose slices, click to fill, and see fraction/decimal/percent update instantly. Kid-friendly, Challenge mode, privacy-first. Games Launch
⌨️ Typing Test 1-minute typing test with live WPM & accuracy graph, gentle feedback, restart, and a printable certificate. Privacy-first, runs client-side. Games Launch
🔎 Word Search Play or build custom word searches — your word list, grid 8–20, diagonals/backwards options, highlights, and printable PDF/PNG (Classroom pack). Privacy-first, all client-side. Games Launch
💣 Minesweeper Classic Minesweeper with a gentle layout, Flag Mode for touch, right-click flags on desktop, timer, remaining mines, and first-click safety. Runs fully client-side for privacy. Games Launch
😀 Emoji Catcher Gentle typing game for kids: type the word on each falling emoji to catch it. One emoji at a time, slower pace for longer words, lives, and scoring by word length. Fully client-side and private. Games Launch
🎯 Pachinko Probability (Galton Board) Interactive Pachinko/Galton board: drop balls through pegs to see a live distribution. Adjustable rows, bias (p), speed, and spawn rate; pseudo-physics arcs with histogram + binomial overlay, mean/SD stats. 100% client-side. Games Launch
🧩 Towers of Hanoi Calm, privacy-first Hanoi puzzle: manual tap/tap moves or auto-solver. Adjustable disks (3–8), speed control, move counter & optimal target (2^n−1), keyboard & screen-reader friendly. 100% client-side. Games Launch
🌀 Maze (Playable) Calm, privacy-first maze game: swipe or use the D-pad/arrow keys. Seeded generator, sizes (15×15–31×31), timer & steps, crumb trail, and brief hint overlay. Keyboard & screen-reader friendly. 100% client-side. Games Launch
🧠 Memory Match — Animal Emoji Flip cards to match pairs. 4×4–6×6 boards, timer, moves, star rating, and local best times. Private, client-side. Games Launch
⭐ Little Star Glider Tap to nudge a star through soft cloud gaps. Simple, cozy arcade with score & best. Private, client-side. Games Launch
⭐ Carbon Footprint Calculator Estimate a personal annual CO₂e footprint from home energy, travel, diet, and spending. Gentle defaults, fully editable factors. Private, client-side. Environment Launch
⭐ Flight Emissions Calculator CO₂ per passenger by distance, seat class, and legs — with passengers, round-trip option, aircraft presets, and RFI toggle for contrails. Private, client-side. Environment Launch
🌞 Solar Energy Calculator Estimate daily kWh and savings from location, tilt, azimuth, and array size (area & efficiency or panels & wattage). Private, client-side. Environment Launch
⭐ Commute Emissions Comparison Compare commute CO₂ across car, bike, bus, and train with editable factors (carpool size, fuel/kWh, grid intensity). Private, client-side. Environment Launch
⭐ Carbon Offset Estimator Estimate trees or renewable kWh needed to offset CO₂. Editable tree growth, survival/buffer, and grid intensity. Private, client-side. Environment Launch
⭐ Home Energy Usage Calculator Add appliances (or presets) to estimate annual kWh, cost, and CO₂. Includes standby, cycles, heat pump COP. Private, client-side. Environment Launch
⭐ Electricity vs. Gas Heating Compare heat pump, electric resistance, and gas boiler on efficiency, energy in, cost, and CO₂. Adjustable COP, prices, and carbon factors. Private, client-side. Environment Launch
⭐ EV vs. Gas Car CO₂ Calculator Compare per-km and lifetime emissions, see break-even distance, and adjust grid/fuel/battery factors. Private, client-side. Environment Launch
🌍 Reusable Cup Impact Calculator Estimate cups avoided and CO₂ saved per year from reusable cups vs single-use. Friendly, editable, client-side. Environment Launch
🌬️ Wind Turbine Output Calculator Calculate turbine power from wind speed & blade size; estimate daily and annual energy. Editable Cp, efficiency, air density, and cut-in/out. Private, client-side. Environment Launch
🌊 Ocean Plastic Decomposition Timer Visualize estimated fragmentation/decomposition times for common plastics across marine environments, with a simple time-lapse. Private, client-side. Environment Launch
🔋 Battery Storage Sizing Tool Estimate needed battery storage for solar: usable & nameplate kWh, autonomy days, module count, and inverter/DC current checks. Private, client-side. Environment Launch
⭐ Reforestation Impact Estimator Friendly estimator of reforestation CO₂ over time. Edit growth, survival, and buffer. Private, client-side. Environment Launch
⭐ Water Footprint Calculator Estimate daily or annual water use across showers, laundry, taps/toilets, dishwasher, outdoor watering, and diet. Private, client-side. Environment Launch
⭐ Greywater Reuse Estimator Estimate potential greywater capture and reuse to toilets/irrigation, with water, sewer, CO₂, and payback savings. Private, client-side. Environment Launch
⭐ Plastic Footprint Calculator Estimate bottles, bags, takeaway and packaging per year — pieces, mass, and optional CO₂e. Private, client-side. Environment Launch
⭐ Paper vs. Digital Impact Calculator Estimate trees, water, and energy saved when documents move from paper to digital. Transparent, editable, client-side. Environment Launch
⭐ Shower Water & Energy Calculator Estimate water use, heating energy (kWh), cost, and CO₂ from flow, time, and temperatures. Private, client-side. Environment Launch
⭐ Waste Reduction Impact Estimate CO₂e saved by recycling vs. landfill/incineration. Fully editable factors; private, client-side. Environment Launch
⭐ Solar Payback Calculator Estimate payback time, cash flow, NPV & IRR from cost, incentives, annual kWh, self-consumption, and tariffs. Private, client-side. Environment Launch
⭐ LED vs. Incandescent Savings Annual kWh & cost savings from LEDs vs incandescents, with optional CO₂ and payback. Private, client-side. Environment Launch
⭐ Rainwater Harvesting Calculator Estimate rooftop rain capture with annual/monthly rainfall, runoff & filter efficiency, first-flush, and optional tank capacity. Private, client-side. Environment Launch
⭐ Urban Heat Reduction Calculator Estimate near-surface air cooling from canopy, shade, green roofs, and cool surfaces. Transparent, editable assumptions. Private, client-side. Environment Launch
⭐ Sound Travel Time Calculator Thunder delay & shout echo calculator with temperature-aware speed of sound. Distance ⇄ time, echo mode. Private, client-side. Science & Engineering Launch
⭐ How Many Helium Balloons to Lift You? Estimate how many helium balloons could pretend-lift a chosen weight. Includes 9″/12″/24″ presets, custom size, kg/lb, and practical margin. Private, client-side. Fun Calculators Launch
⭐ How Many Earths Fit in the Sun? Compare any planet to any other by volume. Shows ideal vs sphere-packing counts and a friendly visual. Private, client-side. Fun Calculators Launch
⭐ Cloud Storage in Floppy Disks Converter Convert modern sizes into counts of retro media (floppies, CDs, DVDs, Blu-ray, Zip/Jaz, VHS). Decimal/binary units, VHS bitrate/length, private & client-side. Fun Calculators Launch
🧠 How Many Tabs Can Your Brain Handle? Estimate comfy vs. stretch tab counts from working-memory capacity, task complexity, and distractions. Private, client-side. Productivity & Focus Launch
☕😴 Coffee-to-Sleep Tradeoff Estimate bedtime delay and sleep loss from caffeine timing and dose with a simple half-life model. Private, client-side. Health & Sleep Launch
⌨️ Keyboard Typing Distance Turn word counts into meters and kilometers of finger travel, with configurable typing assumptions. Private, client-side. Fun Calculators Launch
🧻 Toilet Paper Roll Length Converter Turn toilet paper rolls into meters, kilometers, and fun comparisons (Eiffel Towers, football pitches, blue whales). Private, client-side. Fun Calculators Launch
🐌 Snail Mail Speed Calculator Compare a snail’s travel time (speed & duty cycle) with postal delivery times. Private, client-side. Fun Calculators Launch
🪐 How Much Would You Weigh on Every Planet? Enter Earth weight (kg/lb/N) or mass (kg) and see your weight across the Solar System using real planetary gravity constants. Private, client-side. Fun Calculators Launch
📄 Data → Paper: How Many Pages? Convert a text file size into printed pages with encoding & layout presets. Outputs pages, sheets, reams, paper weight, and stack height. Private, client-side. Fun Calculators Launch
🔊 How Loud Is Too Loud? dB ↔ intensity, pressure, source acoustic power from distance/directivity, and energy over time. Private, client-side. Fun Calculators Launch
⭐ Love Calculator Check playful name chemistry and an optional birthday rhythm boost. Private, client-side. Games Launch
🐶 Dog Years to Human Years (Breed-Aware) Breed/size-aware converter with Classic + DNA curves, months input, and a friendly visual. Private, client-side. Fun Calculators Launch
😴 Perfect Nap Length Calculator Sleep cycle optimizer: power naps (10–20 min) or full cycles (~90–110 min), start/wake planning, latency & chronotype tweaks. Private, client-side. Fun Calculators Launch
⭐ Cells You’ve Replaced — “Every 7 Years” Myth Calculator Explore tissue-by-tissue turnover with plain-English sources. Kid-friendly, private, 100% client-side. Science Launch
⭐ Email Carbon Footprint Estimate the CO₂ footprint of emails and attachments with simple & advanced modes and friendly comparisons. Private, client-side. Fun Calculators Launch

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