HTTP Status Code Reference
Look up any HTTP status code: its meaning, when to use it, and the standard it comes from.
Runs in your browser Your input never leaves your device.
Names and numbers follow RFC 9110 and the IANA registry. Codes marked unofficial are used by nginx or Cloudflare but are not part of the standard. This is a reference list; to test a live URL use the HTTP Status Code Checker.
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About this tool
A reference for the HTTP status codes web servers send, from 100 Continue to 511 Network Authentication Required. Type a code or a few words (404, redirect, rate limit, teapot) to search, or use the 1xx to 5xx buttons to browse a class. Each entry gives the official name, what it means, practical advice on when to use it or how to fix it, and the RFC section that defines it. It follows the current names in RFC 9110, so 413 is Content Too Large and 422 is Unprocessable Content. Common codes that are not part of the standard are included and marked unofficial: nginx 444 and 499, and Cloudflare 520 to 526, which you will see when a site sits behind Cloudflare. To test what a real URL returns, use the HTTP Status Code Checker. The list is static and runs in your browser.
How to use it
- Type a code, or words such as redirect or timeout, in the search box.
- Or press 1xx to 5xx to browse one class.
- Read the meaning and the advice for the code.
- Open the RFC section in the grey line for the exact wording.
Common problems
- What is the difference between 301, 302, 307 and 308?
- 301 and 308 are permanent; 302 and 307 are temporary. 307 and 308 keep the request method (a POST stays a POST), while 301 and 302 let browsers change it to GET.
- 401 or 403?
- 401 means the request has no valid login, so signing in may help. 403 means the server knows who you are and still refuses.
- A code I saw is missing
- Only registered codes and the common nginx and Cloudflare ones are listed. Other products add their own numbers; check that product's documentation.