Developer Reference100% Free Quick ReferenceUpdated 2026-09-04

HTTP Status Codes Cheatsheet: Complete 1xx–5xx Reference

The complete HTTP response status codes guide with meanings, causes, and developer debugging advice.

2xx Success Codes

The request was successfully received, understood, and accepted.

200 OK

Standard response for successful HTTP requests.

200
201 Created

The request succeeded and a new resource was created (common for POST requests).

201
204 No Content

The server processed the request successfully but returns no content body (common for DELETE).

204

3xx Redirection Codes

Further action needs to be taken by the user agent to fulfill the request.

301 Moved Permanently

The requested resource has been assigned a new permanent URI. Crucial for SEO migrations.

301
302 Found

Temporary redirect to a different URI.

302
304 Not Modified

Indicates that the resource has not been modified since the version specified in If-Modified-Since headers.

304
307 Temporary Redirect

Temporary redirect that guarantees the HTTP method (GET/POST) does not change.

307
308 Permanent Redirect

Permanent redirect that guarantees the HTTP method does not change.

308

4xx Client Error Codes

The request contains bad syntax or cannot be fulfilled by the client.

400 Bad Request

The server cannot process the request due to client error (e.g. malformed JSON body or invalid syntax).

400
401 Unauthorized

Authentication is required and has failed or has not yet been provided.

401
403 Forbidden

The client does not have access rights to the content (unlike 401, server knows the client's identity).

403
404 Not Found

The server cannot find the requested resource. The most common error on the web.

404
405 Method Not Allowed

The request method is known by the server but not supported by the target resource (e.g. POST to a GET-only endpoint).

405
429 Too Many Requests

The user has sent too many requests in a given amount of time (rate limited).

429

5xx Server Error Codes

The server failed to fulfill an apparently valid request.

500 Internal Server Error

A generic error message indicating an unexpected condition occurred on the server.

500
502 Bad Gateway

The server, while acting as a gateway or proxy, received an invalid response from an inbound server.

502
503 Service Unavailable

The server is currently unable to handle the request due to maintenance or capacity overload.

503
504 Gateway Timeout

The gateway server did not receive a timely response from the upstream server.

504

FAQ

Frequently Asked Questions

What is the difference between 401 Unauthorized and 403 Forbidden?

401 Unauthorized means you are unauthenticated (not logged in). 403 Forbidden means the server knows who you are, but you lack sufficient permissions to view the resource.

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