UUIDv4 Generator (Random)
Generate up to 200 random UUIDs with color-coded parts.
Legend:
XXXXXXXX = time_low XXXX = time_mid 4XXX = time_hi_and_version XXXX = clock_seq XXXXXXXXXXXX = node
XXXXXXXX = time_low XXXX = time_mid 4XXX = time_hi_and_version XXXX = clock_seq XXXXXXXXXXXX = node
Understanding UUIDv4
A UUID (Universally Unique Identifier) is a 128-bit value commonly used to identify information in distributed systems. UUID version 4 is generated entirely from random numbers, providing a very high probability of uniqueness.
Why Use UUIDv4?
- Uniqueness: With 122 random bits, collisions are practically impossible.
- Randomness: It does not rely on timestamps or hardware identifiers, making it harder to predict.
- Simplicity: It’s widely supported across programming languages and databases.
UUIDv4 Structure
A UUIDv4 has the form xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx:
- time_low: 8 hex digits (red)
- time_mid: 4 hex digits (green)
- time_hi_and_version: 4 hex digits, always starting with
4(blue) - clock_seq: 4 hex digits (gold)
- node: 12 hex digits (purple)
How This Tool Works
The tool uses the browser's built-in crypto.getRandomValues() to create 16 random bytes, then sets the appropriate bits for version (4) and variant (RFC 4122).
Everything is computed client-side — no data is sent anywhere.