HTTP Status Codes Reference
Look up any HTTP status code in seconds. Search by code or keyword, then explore semantics, caching, SEO and REST notes — all in your browser.
HTTP Status Lookup
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How It Works
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Type a 3-digit code or keyword into the search box.
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Frequently Asked Questions
What is an HTTP status code?
An HTTP status code is a three-digit number returned by a server in response to a client request. It indicates whether the request was successful, redirected, or encountered an error.
What are the most common codes?
The most common are: 200 (OK), 301 (Moved Permanently), 304 (Not Modified), 400 (Bad Request), 401 (Unauthorized), 403 (Forbidden), 404 (Not Found), 500 (Internal Server Error), and 503 (Service Unavailable).
What do 4xx codes mean?
4xx codes indicate client errors. The request contains bad syntax, cannot be fulfilled, or is otherwise the client's fault.
What do 5xx codes mean?
5xx codes indicate server errors. The server failed to fulfill a valid request, which usually requires server-side investigation.
Is 418 a real status code?
Yes — 418 "I'm a teapot" is a humorous code from the HTCPCP protocol (RFC 2324). It's officially registered but used mostly as an easter egg.
Where does my query go?
Nowhere. Every search is processed 100% in your browser — nothing is sent to a server.