HTTP Status Codes Reference — All HTTP Response Codes Explained

Complete HTTP status codes reference — search any code or browse all 1xx, 2xx, 3xx, 4xx and 5xx codes with clear descriptions.

Also test patterns with our Regex Tester or decode tokens with the JWT Decoder.

How to Use

How to Use the HTTP Status Codes Reference

1
Search instantly — type a code number (e.g. 404) or keyword (e.g. "not found") into the search box to filter the list immediately.
2
Browse by category — clear the search to see all codes grouped by colour: blue (1xx), green (2xx), yellow (3xx), red (4xx/5xx).
3
Read the description — each code shows its name and a plain-English explanation of what it means.
4
Reference anytime — bookmark this page for a fast, ad-light HTTP status code cheat sheet during development and debugging.
About

HTTP Status Code Categories Explained

HTTP status codes are three-digit numbers returned by a web server in response to an HTTP request. They are grouped into five ranges based on their first digit. This HTTP status codes reference works as an HTTP response code guide, API error code reference, and web developer cheat sheet for understanding what each code means during development and debugging.

1xx Informational codes indicate that the request was received and the server is continuing to process it. The most common is 100 Continue, sent when the server has received request headers and the client should proceed to send the body.

2xx Success codes confirm the request was successfully received, understood, and accepted. 200 OK is the standard success response. 201 Created is returned when a new resource has been created, common in REST API POST endpoints. 204 No Content is returned when the request succeeded but there is no body to return — common in DELETE operations.

3xx Redirection codes indicate the client must take additional action to complete the request. 301 Moved Permanently is used for SEO-preserving redirects when a URL changes permanently. 302 Found is a temporary redirect. 304 Not Modified tells the browser its cached version is still current, reducing bandwidth.

4xx Client Error codes indicate the request contains an error on the client side. 400 Bad Request means malformed syntax. 401 Unauthorized means authentication is missing. 403 Forbidden means authenticated but not permitted. 404 Not Found is the most commonly encountered error. 429 Too Many Requests indicates rate limiting.

5xx Server Error codes indicate the server failed to fulfil a valid request. 500 Internal Server Error is the generic catch-all. 502 Bad Gateway and 503 Service Unavailable are common in load-balanced or microservice environments where an upstream dependency is down.

FAQ

Frequently Asked Questions

HTTP status codes are three-digit numbers returned by a server in response to an HTTP request. They indicate whether the request was successful, resulted in a redirect, or encountered an error.
A 404 Not Found error means the server could not find the requested resource at the given URL. The page may have been deleted or the URL may be incorrect.
401 Unauthorized means authentication is required — the user is not logged in. 403 Forbidden means the server understood the request but refuses to authorize it — the user is logged in but does not have permission.
A 500 Internal Server Error is a generic server-side error that occurs when something goes wrong on the server and no more specific error code is applicable. Common causes include unhandled exceptions, configuration errors, or database connection failures.
Related tools

Related Free Tools

🔍
Regex Tester
🔐
JWT Decoder
🔑
Base64 Encoder
📊
JSON to CSV