HTTP status codes
Look up what an HTTP response code means. Search by number, name or keyword, or filter by class: informational, success, redirection, client error and server error. Every code in the IANA registry is listed.
Runs in your browser: nothing you enter is sent anywhere.
How to use it
- Type a number (
404), a name (gateway) or a keyword (redirect) in the search box. Several words must all match.
- Use the class buttons to see only one kind of response.
- Each entry shows the code, its official name, what it means, and the document that defines it.
How the classes work
| Class |
Meaning |
Examples |
| 1xx |
Informational: keep going |
100, 101, 103 |
| 2xx |
Success |
200, 201, 204 |
| 3xx |
Redirection: more action needed |
301, 304, 308 |
| 4xx |
Client error |
400, 404, 429 |
| 5xx |
Server error |
500, 502, 503 |
Tips
Most codes are defined in RFC 9110 (HTTP Semantics), which replaced the older RFC 7231. When designing an API, choose the most specific code that fits: 201 after creating something, 204 when there is nothing to return, 422 for failed validation, and 429 with a Retry-After header for rate limits.
Frequently asked questions
What are the five classes of HTTP status codes?
1xx codes are informational, 2xx mean success, 3xx are redirects, 4xx mean the client made an error, and 5xx mean the server failed on a request that looked valid. The first digit alone tells you which kind of response you have.
What is the difference between 301 and 302 redirects?
301 says the move is permanent, so browsers and search engines should update their links to the new address. 302 says it is temporary, so the old address stays the main one. 307 and 308 are the strict versions that never change the request method.
What is the difference between 401 and 403?
401 means the request has no valid credentials, so logging in may fix it. 403 means the server knows who you are, or does not care, and refuses anyway, so new credentials will not help unless they belong to someone with permission.
Is 418 a real status code?
418 I'm a teapot comes from RFC 2324, the Hyper Text Coffee Pot Control Protocol, published as an April Fools' joke in 1998. The IANA registry keeps it reserved as unused, and the list shows it so you know what you are looking at.
Which codes are listed?
Every code in the IANA HTTP Status Code Registry between 100 and 511, including WebDAV ones such as 207 and 423. Unofficial codes used by single vendors, such as Cloudflare's 5xx extensions or nginx's 499, are not part of the registry and are not listed.