1xx — Informational
The server received the request and is continuing. Browsers and Fetch usually handle interim responses without exposing them to page scripts.
HTTP Status Code Checker & Reference
Check a URL
The target must permit cross-origin browser access for its status to be readable.
Direct and credential-free: this page does not submit your entered URL to Starlight Tools. Your browser contacts the target with cookies and HTTP authentication omitted and no referrer. The target still receives your IP address and ordinary browser request headers.
Check result
Enter a complete URL and select Check status. Results appear here without resizing the tool card.
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HTTP status code reference
Registered and reserved codes in the IANA HTTP Status Code Registry, including temporary 104.
What the status classes mean
2xx — Success
The server successfully received, understood, and accepted the request. A 2xx response does not guarantee that the returned content is semantically correct.
3xx — Redirection
More action is needed, often following another URL or using a cached representation. This checker follows redirects and reports the final readable response.
4xx — Client error
The request cannot be fulfilled as sent. Authentication, permissions, syntax, rate limits, and missing resources are common causes.
5xx — Server error
The server failed while handling an apparently valid request. The origin, gateway, proxy, or an upstream service may be responsible.
How to check and interpret a response
- Paste the full URL. Include
https://orhttp://. Embedded usernames and passwords are rejected. - Choose GET or HEAD. GET most closely resembles a normal navigation. HEAD asks for headers without a response body, but not every server implements it correctly.
- Run the check. The browser follows redirects, omits cookies and HTTP credentials, and stops after the selected timeout.
- Read the final response. The status, class, redirect flag, final URL, and elapsed browser time can be copied or downloaded. Timing is not a controlled performance benchmark.
Important browser limit: cross-origin status access requires the target to return a suitable Access-Control-Allow-Origin header. CORS, mixed-content policy, DNS errors, TLS failures, extensions, or network filtering can all produce the same browser-level failure. That failure is not proof that the target is offline.
GET, HEAD, redirects, and privacy
| Choice | What happens | Use it when |
|---|---|---|
| GET | Requests the representation and may transfer its body before the browser makes status details available. | You want the result closest to a normal page or API request. |
| HEAD | Requests the same headers as GET should return, without a response body. Some servers reject or mishandle HEAD. | You control the endpoint or know it supports HEAD. |
| Redirect follow | The Fetch API follows redirects. The page can report the final URL and a redirected flag, but not a full cross-origin hop history. | You need the final browser-readable response. |
| Credentials omitted | Cookies, client certificates selected as Fetch credentials, and HTTP authentication credentials are omitted by the request configuration. | You want an unauthenticated check; this may differ from your signed-in browser tab. |
The checker does not store a history and its code does not send the URL or report to Starlight Tools. A live request still discloses your network address and browser-level request metadata to the target. Avoid checking sensitive, signed, or single-use URLs on a shared device, and remember that a poorly designed endpoint might incorrectly change state in response to GET.
Reference definitions reviewed against the IANA HTTP Status Code Registry, RFC 9110 HTTP Semantics, and the WHATWG Fetch Standard on . Code 104 is a temporary registration scheduled to expire on 13 November 2026 unless renewed.
HTTP status checker FAQ
Why can this checker be blocked by CORS?
The request goes directly from this page to the target. For a different origin, the target must opt into browser access with CORS. If it does not, JavaScript cannot read the status even when the server returned one. Use a CORS-enabled endpoint, your browser’s Network panel, curl, or a trusted server-side checker.
Does the checker follow redirects?
Yes. Fetch follows redirects and exposes the final readable response, its URL, and whether a redirect occurred. It does not expose the complete cross-origin redirect chain to this page.
Should I use GET or HEAD?
Use GET for the most representative result. HEAD can save bandwidth because it requests no body, but some sites disable it or return a status that differs from GET.
Why does a result differ from curl or uptime monitoring?
Browsers enforce CORS, mixed-content, and other security rules. Authentication, cookies, user agent, IP address, geography, CDN routing, request method, bot controls, and caching can also produce different responses.
Does a 2xx code mean the page is working correctly?
It means the HTTP request succeeded at the protocol level. The response can still contain an application error, incomplete data, stale content, or an unexpected page.
Is 304 an error?
No. 304 Not Modified tells a conditional client to reuse its cached representation. A basic uncached checker may not receive it because it has not supplied the same validators as a returning browser.
Is 418 really “I’m a teapot”?
RFC 9110 now labels 418 as unused. The joke code became widely deployed, so IANA reserves it instead of assigning it a new meaning.