HTTP Status Code Reference
Browse HTTP status codes (1xx-5xx) with descriptions and filter by number or keyword. A quick reference while developing and debugging. Search runs entirely in your browser.
Examples (click to filter)
How to Use the HTTP Status Code Reference
Type a code number or keyword to narrow the list to matching codes. A chip filters to that number instantly; Show all clears it. A partial number (for example 40) or part of a status name also matches.
Examples
- 404 → 404 Not Found (the resource does not exist)
- 301 → 301 Moved Permanently (the URL has moved for good)
- 500 → 500 Internal Server Error (an unexpected server-side error)
- 429 → 429 Too Many Requests (a rate limit was reached)
- 503 → 503 Service Unavailable (temporarily down from overload or maintenance)
Useful While Debugging
Keep this open when inspecting API responses, browser network panels, redirects and failed fetch requests. The code category gives the first clue: 2xx means success, 3xx means redirect, 4xx usually points to the request, and 5xx usually points to the server.
FAQ
Is my data sent to a server?
No. Searching and filtering run entirely in your browser; nothing is transmitted or stored externally.
301 vs 302?
301 Moved Permanently is a permanent move: browsers and search engines transfer link signals to the new URL and cache the result. 302 Found is temporary, so the original URL stays canonical and is not cached. Use 301 for permanent moves (including SEO), and 302 for temporary redirects such as during maintenance.
401 vs 403?
401 Unauthorized means authentication is required or failed; you may get in after authenticating correctly. 403 Forbidden means access is denied regardless of authentication, so logging in again will not help. Typical causes are insufficient permissions or IP restrictions.
Why do I get 429 Too Many Requests?
You exceeded the allowed number of requests per time window (rate limiting). The server may send a Retry-After header indicating how long to wait. The standard client response is to retry with exponential backoff.
404 vs 410?
404 Not Found only says the resource cannot be found and does not rule out the URL coming back later. 410 Gone states that the resource existed and was removed for good, which tells caches and crawlers that retrying is pointless. Both are failures from the client side, but they communicate different intent. Note that 410 is not part of this list.
Are any codes missing from this list?
Yes. The list covers the 19 codes you meet most often in practice, so 410 Gone, 307 Temporary Redirect, 308 Permanent Redirect and 451 Unavailable For Legal Reasons are not included. Implementation-specific numbers such as Cloudflare 520-527 or nginx 499 are also out of scope. RFC 9110 is the primary source for the formal definitions.