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HTTP Status Codes

Searchable reference for all HTTP status codes (1xx–5xx). Filter by category, copy responses, see usage examples.

About this tool

Every HTTP response carries a three-digit status code that tells the client what happened. Codes are grouped into five classes: 1xx informational, 2xx success, 3xx redirection, 4xx client errors, and 5xx server errors. Knowing the right code for each situation makes APIs predictable and debugging faster.

Type a number like 404 or a word like redirect to filter instantly. Click any card to expand a plain-English explanation and a real-world "when to use" example, then copy the response line. Shareable links: ?code=503 opens a specific code, and the URL hash tracks your filter and search.

Common mix-ups: 401 means "not logged in", 403 means "logged in but not allowed"; 302 may change the method to GET while 307 preserves it; 422 is for semantically invalid (but well-formed) data, whereas 400 is for malformed input.

FAQ

What is the difference between 401 Unauthorized and 403 Forbidden?

401 means the server does not know who you are — you must authenticate (log in, provide a token). 403 means the server knows who you are but you lack permission for this specific resource. Sending 403 instead of 401 also avoids leaking whether an account exists.

When should I use 302 vs 307 (or 301 vs 308)?

302 and 301 are historical redirects that, in practice, may convert a POST into a GET. 307 and 308 were introduced to guarantee the HTTP method and body are preserved across the redirect. Use 307/308 whenever the method must not change (e.g. redirecting a form POST).

Is 418 I'm a Teapot a real status code?

It comes from RFC 2324, an April Fools' specification for a hyper-text coffee pot protocol. It is not part of HTTP proper, but many APIs return it as an Easter egg or for "I refuse to process this" — never use it for real error handling.

What does 451 Unavailable For Legal Reasons mean?

Introduced in RFC 7725, it signals that a resource is blocked for legal reasons such as a government takedown, court order, or DMCA notice. The number is a reference to the novel Fahrenheit 451. Responses often include a `Link` header pointing to an explanation.

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