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Look up HTTP status codes

HTTP status code reference answers what a code means, however you ask. Type a number such as 404, a class such as 4xx, or a word such as timeout, and the matching codes appear with a plain-English explanation of each. With the box empty it lists every code by class. The table has the 62 codes registered with IANA, from 100 Continue to 511 Network Authentication Required, including the WebDAV codes and newer ones such as 103, 425 and 451.

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How to use HTTP Status Codes

  1. Open HTTP Status Codes in the Toolbox101 app.
  2. Type a code (404), a class (4xx) or a word (timeout) into the Code or keyword box. Leave it empty to list every code.
  3. Read the matches in the Output box: each code, its reason phrase and a one-sentence explanation.
  4. Click Copy to keep the answer for a ticket, a code comment or an API error handler.

Worked example

HTTP Status Codes returns the output below for this input.

Input

404

Output

404 Not Found
The server cannot find the requested resource. The URL may be wrong, or the resource was removed. Sometimes used to hide that a resource exists.

Check it yourself: open HTTP Status Codes and enter the same input.

Frequently asked questions

What is the difference between 401 and 403?

401 Unauthorized means the request has no valid credentials, so the client must authenticate, typically by sending an Authorization header. 403 Forbidden means the server understood the request and refuses it: the credentials, if any, are fine but do not give access. Both reject the request, for different reasons.

Can I search by word instead of number?

Yes. Any words you type must all appear in a code's name or explanation. timeout finds 408 Request Timeout and 504 Gateway Timeout, and redirect finds the 3xx codes that describe themselves that way. A class such as 5xx lists every code in that class.

What do 301, 302, 307 and 308 mean?

301 and 308 are permanent redirects, 302 and 307 temporary ones. The difference within each pair is the method: browsers may turn a POST into a GET after a 301 or 302, while 307 and 308 must keep the method and body.

Why does my code say it is not a standard status code?

The table holds the codes registered with IANA. A code outside it, such as 499 (nginx's marker for a client that closed the connection) or Cloudflare's 52x errors, is not standard and gets that message. Check the documentation of the product that sends it.

What is the reason phrase after a status code?

The reason phrase is the human-readable text after the number in a response status line, such as OK after 200. It is informational: clients branch on the numeric code, and servers may send a custom phrase, so treat the number as the contract and the phrase as a description.

Use HTTP Status Codes now

Open HTTP Status Codes in the app

Runs in your browser. Nothing you type is uploaded.