HTTP Codes & MIME Types

What it's for

Find out what an HTTP status code means, or which Content-Type a kind of file should be served with, without searching the web.

For example, when an API call fails with 422, type it in to see that the request was well formed but its content failed validation, so the fix is in the data you sent, not the URL.

How to use it

Type into the search box and both lists narrow as you type. Search by:

• A code, such as 404, or a class: 4xx (or just 4) shows every client error.
• A word in the name or meaning, such as redirect, cache or rate.
• A file extension, with or without the dot (.webp, docx), or part of a MIME type (json, font/).

Every word you type must match, so redirect method finds the redirects that keep the request’s method. Copy a link to this input keeps the search.

Example

Choose Try an example, which searches for 4xx: the list shows the client errors from 400 Bad Request to 451 Unavailable For Legal Reasons, and no file types.

Good to know

The status codes are those registered with IANA, plus 418. Servers and frameworks sometimes use unregistered codes (such as Cloudflare’s 520 to 527 or nginx’s 499), which aren’t listed. The MIME types cover common files only; the full IANA list has thousands.