HTTP Status Codes Reference
Every common HTTP status code from 1xx to 5xx, colour-coded by category, with its official name and what it actually means. Filter by number, name or keyword — and yes, 418 I'm a teapot is here.
| Code | Name | Category | Meaning |
|---|
An HTTP status code is the three-digit number a web server sends back at the start of every response. It is the server's one-word verdict on your request: did it work, do you need to go somewhere else, did you make a mistake, or did the server itself fall over? Your browser usually hides these codes when things go well, but they are the backbone of debugging websites and APIs.
The first digit sets the class. 1xx responses are informational and rarely seen. 2xx means success — 200 OK is the happy path of the web. 3xx asks the client to look elsewhere, usually via a redirect. 4xx blames the request: the classic 404 Not Found means the URL points at nothing. 5xx blames the server: 500 Internal Server Error and 502 Bad Gateway mean the request was fine but the server could not fulfil it.
Status 418 I'm a teapot comes from RFC 2324, an April Fools' joke from 1998 defining a protocol for coffee pots. It will never appear in real traffic, but it is baked into countless frameworks as a running gag — and it is a great way to test that your error handling passes codes through untouched.
Getting status codes right matters far beyond aesthetics. Search engines treat a 301 and a 302 very differently, monitoring tools alert on 5xx spikes, and REST APIs rely on 201 Created, 204 No Content and 429 Too Many Requests to communicate cleanly with clients. Returning the wrong code — like a 200 on a page that failed — quietly breaks caching, crawling and automated retries.
To see status codes in the wild, learn how the secure transport underneath works in HTTP vs HTTPS. When you are chasing down where a request actually goes, combine this reference with our DNS Lookup and HTTP Ping Test tools.
Frequently asked questions
What do the HTTP status code categories mean?
Codes are grouped by their first digit: 1xx informational, 2xx success, 3xx redirection, 4xx client errors (the request was wrong), and 5xx server errors (the server failed while handling a valid request).
What is the difference between a 301 and a 302 redirect?
A 301 Moved Permanently tells clients and search engines the resource has moved for good, so they should update bookmarks and pass link value to the new URL. A 302 Found is temporary, so the original URL should keep being used. For SEO, use 301 when a page has permanently moved.
Is 418 I'm a teapot a real status code?
It is officially reserved by RFC 2324, the Hyper Text Coffee Pot Control Protocol — an April Fools' joke. It is never used for real web traffic but is implemented by many servers and frameworks as an in-joke.
What status code should a successful API request return?
Use 200 OK for a successful request that returns data, 201 Created when a new resource was created (often with a Location header), and 204 No Content when the request succeeded but there is nothing to return, such as a delete.
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