HTTP Status Codes Reference
Every registered HTTP status code with reason phrase, RFC and one-line meaning — search by number, class, phrase or word — plus Nginx, Cloudflare, AWS codes.
The code you looked up with its RFC and meaning, cacheable / retry hints, or a filtered list by class or word, with unofficial vendor codes marked as such.
Example: 404 Not Found (RFC 9110 §15.5.5, cacheable); "timeout" finds 408, 504, 524, 598, 599; 499 is Nginx's client-closed-request, not a registered code; 42 lists 420–429.
The IANA registry,
in one searchable list.
Where the data comes from, how search works, and what the unofficial codes are.
The list
Every code in the IANA HTTP Status Code Registry with the reason phrase and section of the RFC that defines it — RFC 9110 for the core codes, RFC 4918 and 5842 for WebDAV, RFC 6585, 7725, 8297, 8470 and the historic 2295, 2324, 2774 and 3229 for the rest. The one-line meanings are summaries written for this page, not the normative text; follow the RFC reference when it matters.
Searching
A three-digit number finds that code; a shorter prefix such as 4 or 42 lists a range; any other text is matched against the phrase, the meaning and the source, so "redirect", "auth" or "teapot" work. The class buttons filter to 1xx–5xx. The cacheable and retry hints follow RFC 9110's heuristically-cacheable list and the codes that carry Retry-After — hints, not rules for any particular API.
Unofficial codes
Nginx (444, 494–499), Cloudflare (520–530), AWS load balancers (460, 463, 561), IIS and a few frameworks return codes that are not registered. They are listed, marked unofficial, and attributed to the vendor whose documentation defines them, because they show up in logs and people look them up. Nothing leaves the browser; the same four anonymous usage counts as the rest of the site apply.
SOURCES
- IANA Hypertext Transfer Protocol (HTTP) Status Code Registry; RFC 9110 §15 and RFC 4918, 5842, 6585, 7725, 8297, 8470, 2295, 2324 for the codes they define; vendor documentation for unofficial codes
Last reviewed 22 September 2026. How results are checked: How we verify.