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HTTP Status Code Reference

Look up any HTTP status code in a searchable, filterable table. Search by number or name, filter by class from 1xx to 5xx, and expand any code for a plain explanation and a link to the spec. Includes the common non-standard codes from nginx, Cloudflare and others.

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Status codes

All 63 status codes

1xx Informational

The request was received and the process continues.

2xx Success

The request was received, understood and accepted.

3xx Redirection

Further action is needed to complete the request.

4xx Client error

The request is faulty or cannot be served as sent.

5xx Server error

The server failed to fulfil a valid request.

About the HTTP Status Code Reference

This tool is a searchable reference for HTTP status codes. Type a number like 404 or a word like redirect and the matching codes filter down as you go, each with a short plain-English meaning. Open any code for a fuller explanation of when it is used and a link to the RFC that defines it.

Codes are grouped and color coded by class, from 1xx through 5xx, so you can see at a glance whether a code means success, a redirect, a client mistake or a server fault. The well-known non-standard codes from nginx, Cloudflare, Apache and a few others are one toggle away when you need them.

What you can do

  • Look up what an HTTP status code means, by number or by name.
  • Filter to a single class, from 1xx informational to 5xx server errors.
  • Tell apart codes people mix up, like 301 and 302 or 401 and 403.
  • Read when to use each redirect and error code, with the defining RFC linked.
  • Find the non-standard codes like nginx 499 and Cloudflare 521 to 526.
  • Copy a code and its reason phrase, ready to drop into docs or a response.

How to use the HTTP Status Code Reference

  1. 1Type a code number or a keyword into the search box, or pick a class to browse.
  2. 2Scan the list, where each row shows the code, its name and a one-line meaning.
  3. 3Open a row for the full description and a link to the spec that defines it.
  4. 4Turn on non-standard codes if you are chasing a vendor-specific status.

What the five classes mean

The first digit of a status code sets its class. 1xx is informational, a hint that the request was received and work continues. 2xx means success. 3xx is redirection, where more steps are needed to finish the request. 4xx is a client error, so the request was faulty or is not allowed. 5xx is a server error, where a valid request could not be fulfilled because something went wrong on the server side.

Reading the class first is often enough to know who has to fix a problem: a 4xx points back at the request, while a 5xx points at the server.

Standard codes and vendor codes

Most codes here come from the IANA registry and RFC 9110, the current specification for HTTP semantics, with WebDAV and a handful of extension RFCs covering the rest. Each standard code links to the RFC that defines it.

Servers and services also return codes that no standard defines. nginx has a family of 4xx and 499 codes, Cloudflare uses 520 to 526 for problems reaching an origin, and frameworks like Laravel add their own. These are marked non-standard and hidden until you switch them on, so the default list stays true to the specification.

Codes that get confused

A few pairs trip people up. 301 is a permanent redirect and 302 is temporary, which changes how browsers and search engines treat the old URL. 307 and 308 are the newer versions that keep the request method intact, so a POST stays a POST. 401 means you are not authenticated, while 403 means you are but still not allowed. Searching the name or reading the descriptions side by side makes the difference clear.

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