HTTP Status Code Lookup
Search every standard HTTP status code by number or name and read what it actually means — from 100 Continue all the way to 511 Network Authentication Required.
🔒 Processed locally in your browser
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How to use
- Type a status code into the search box — 404, 301 or 500, for example.
- Or search by name instead: typing "gateway" surfaces both 502 Bad Gateway and 504 Gateway Timeout.
- Partial numbers work too — "40" lists the whole 400–409 range at once.
- Read the description under each code to see what it means and when a server would send it.
- Press Reset to clear the search and browse the complete registry again.
Features
- Covers every status code in the IANA HTTP Status Code Registry, from 100 to 511
- Search by number or by name, with partial matches and no case sensitivity
- Each code comes with a practical explanation, not just its one-line official title
- Results stay grouped by class (1xx to 5xx) so related codes are easy to compare
- The whole registry ships with the page — nothing you type is ever sent anywhere
Frequently asked questions
What do the five HTTP status classes mean?
The first digit tells you the category of the response. 1xx (Informational) means the request was received and the server is still working on it. 2xx (Success) means the request was understood and handled. 3xx (Redirection) means something further is needed, usually following a different URL. 4xx (Client Error) means the request itself was at fault — a bad path, missing credentials or an unsupported method. 5xx (Server Error) means the request looked fine but the server failed to fulfil it.
What's the difference between 301, 302, 307 and 308?
All four are redirects, but they differ on permanence and on what happens to the HTTP method. 301 Moved Permanently and 308 Permanent Redirect say the resource has a new home for good, so browsers and search engines should update their links. 302 Found and 307 Temporary Redirect say the move is temporary and the original URL should stay in use. The newer pair, 307 and 308, guarantee the method and body are preserved, whereas many clients historically turned a POST into a GET when following 301 or 302. Use 301 for permanent moves where compatibility matters most, and 308 when a POST has to stay a POST.
When should a server return 410 instead of 404?
404 Not Found simply says there is no resource at that URL right now — it may never have existed, it may have moved, it may come back tomorrow. 410 Gone is deliberate and final: the resource did exist here and has been intentionally removed with no forwarding address. Search engines treat 410 as the stronger signal and tend to drop the URL from their index faster. Use 410 when you retire content on purpose, and 404 for everything else, including plain typos.
What does a 500 error tell me?
A 5xx code means the failure is on the server's side, not yours. As a visitor there is usually nothing to fix — reloading in a few minutes is all you can do, and clearing your cache won't help because your request was fine. As a developer, 500 Internal Server Error is a catch-all for an unhandled exception, so the real cause lives in your application logs or stack trace rather than in the status code. The more specific 5xx codes narrow it down: 502 and 504 point at an upstream service or proxy, while 503 usually means overload or a maintenance window.
Where does this data come from, and are my searches sent anywhere?
The codes and descriptions come from the IANA HTTP Status Code Registry and the RFCs behind it, chiefly RFC 9110. The whole list is bundled into this page, and filtering runs entirely in your browser as you type. Nothing is sent to a server, no lookup is logged, and the tool keeps working offline once the page has loaded.