HTTP Status Codes Reference

What are HTTP Status Codes?

HTTP status codes are three-digit numbers returned by web servers to indicate the result of a client's request. They are grouped into five classes: 1xx (informational), 2xx (success), 3xx (redirection), 4xx (client errors), and 5xx (server errors). This reference includes all standard codes with descriptions, common causes, and troubleshooting tips.

Common use cases

Quickly looking up what a specific status code means
Debugging API responses with unexpected status codes
Understanding redirect chains (301 vs 302 vs 307)
Choosing the correct status code for API endpoints
Troubleshooting 4xx and 5xx errors in web applications

How to use

1Type a status code like 404, or a word like timeout, in Search — an exact code opens its card.
2Narrow the list with the 1xx–5xx class filter and expand any code for causes, example headers and related codes.
3Copy an example response, or Copy JSON to export the codes shown.

Frequently asked questions

What is the difference between 301 and 302 redirects?

301 (Moved Permanently) tells browsers and search engines the URL has changed permanently — bookmarks and SEO value transfer to the new URL. 302 (Found) is a temporary redirect — the original URL should still be used in the future.

What does 403 Forbidden mean vs 401 Unauthorized?

401 means the request lacks valid authentication credentials — the user needs to log in. 403 means the server understood the request but refuses to authorize it — the user is authenticated but doesn't have permission.

Status codes

100Continue1xx InformationalThe server has received the request headers and the client should proceed to send the request body.

101Switching Protocols1xx InformationalThe server is switching protocols as requested by the client via the Upgrade header.

102Processing1xx InformationalThe server has received and is processing the request, but no response is available yet.

103Early Hints1xx InformationalUsed to return some response headers before the final HTTP message.

200OK2xx SuccessThe request succeeded. The meaning depends on the HTTP method used.

201Created2xx SuccessThe request succeeded and a new resource was created as a result.

202Accepted2xx SuccessThe request has been accepted for processing, but the processing has not been completed.

203Non-Authoritative Information2xx SuccessThe returned metadata is from a local or third-party copy, not the origin server.

204No Content2xx SuccessThe server successfully processed the request but is not returning any content.

205Reset Content2xx SuccessThe server processed the request and asks the client to reset the document view.

206Partial Content2xx SuccessThe server is delivering only part of the resource due to a Range header sent by the client.

207Multi-Status2xx SuccessConveys information about multiple resources in situations where multiple status codes might be appropriate.

208Already Reported2xx SuccessMembers of a DAV binding have already been enumerated in a previous reply and are not included again.

226IM Used2xx SuccessThe server has fulfilled a GET request with instance-manipulations applied to the current instance.

300Multiple Choices3xx RedirectionThe request has more than one possible response and the user or agent should choose one.

301Moved Permanently3xx RedirectionThe resource has been permanently moved to a new URL. Update bookmarks.

302Found3xx RedirectionThe resource is temporarily located at a different URI. Continue using the original URI.

303See Other3xx RedirectionThe response to the request can be found at another URI using a GET method.

304Not Modified3xx RedirectionThe resource has not been modified since the version specified by the request headers.

307Temporary Redirect3xx RedirectionThe resource is temporarily at another URI. The request method must not change.

308Permanent Redirect3xx RedirectionThe resource has permanently moved. The request method must not change.

400Bad Request4xx Client errorThe server cannot process the request due to malformed syntax or invalid parameters.

401Unauthorized4xx Client errorAuthentication is required and has failed or has not been provided.

402Payment Required4xx Client errorReserved for future use. Sometimes used for digital payment systems.

403Forbidden4xx Client errorThe server understood the request but refuses to authorize it.

404Not Found4xx Client errorThe server cannot find the requested resource. The URL is not recognized.

405Method Not Allowed4xx Client errorThe HTTP method used is not supported for the requested resource.

406Not Acceptable4xx Client errorThe server cannot produce a response matching the client's Accept headers.

407Proxy Authentication Required4xx Client errorThe client must first authenticate itself with the proxy.

408Request Timeout4xx Client errorThe server timed out waiting for the request from the client.

409Conflict4xx Client errorThe request conflicts with the current state of the server.

410Gone4xx Client errorThe resource is no longer available and will not be available again.

411Length Required4xx Client errorThe server requires a Content-Length header in the request.

412Precondition Failed4xx Client errorOne or more conditions in the request headers evaluated to false.

413Content Too Large4xx Client errorThe request body is larger than the server is willing or able to process.

414URI Too Long4xx Client errorThe URI provided in the request is too long for the server to process.

415Unsupported Media Type4xx Client errorThe media format of the requested data is not supported by the server.

416Range Not Satisfiable4xx Client errorThe range specified in the Range header cannot be fulfilled by the server.

417Expectation Failed4xx Client errorThe server cannot meet the requirements of the Expect request-header field.

418I'm a Teapot4xx Client errorThe server refuses to brew coffee because it is, permanently, a teapot.

421Misdirected Request4xx Client errorThe request was directed at a server that is not able to produce a response.

422Unprocessable Content4xx Client errorThe request is well-formed but contains semantic errors that prevent processing.

423Locked4xx Client errorThe resource that is being accessed is locked.

424Failed Dependency4xx Client errorThe request failed because it depended on another request which failed.

425Too Early4xx Client errorThe server is unwilling to risk processing a request that might be replayed.

426Upgrade Required4xx Client errorThe server refuses to perform the request using the current protocol.

428Precondition Required4xx Client errorThe server requires the request to be conditional (e.g., include If-Match).

429Too Many Requests4xx Client errorThe user has sent too many requests in a given amount of time (rate limiting).

431Request Header Fields Too Large4xx Client errorThe server refuses the request because the header fields are too large.

451Unavailable For Legal Reasons4xx Client errorThe resource is unavailable due to legal demands (e.g., censorship or court order).

500Internal Server Error5xx Server errorThe server encountered an unexpected condition that prevented it from fulfilling the request.

501Not Implemented5xx Server errorThe server does not support the functionality required to fulfill the request.

502Bad Gateway5xx Server errorThe server received an invalid response from an upstream server.

503Service Unavailable5xx Server errorThe server is not ready to handle the request, usually due to maintenance or overload.

504Gateway Timeout5xx Server errorThe server, acting as a gateway, did not receive a timely response from the upstream server.

505HTTP Version Not Supported5xx Server errorThe server does not support the HTTP protocol version used in the request.

506Variant Also Negotiates5xx Server errorThe server has an internal configuration error during content negotiation.

507Insufficient Storage5xx Server errorThe server cannot store the representation needed to complete the request.

508Loop Detected5xx Server errorThe server detected an infinite loop while processing the request.

510Not Extended5xx Server errorFurther extensions to the request are required for the server to fulfill it.

511Network Authentication Required5xx Server errorThe client needs to authenticate to gain network access (e.g., captive portal).

Status code summary

What are HTTP Status Codes?

Common use cases

How to use

Frequently asked questions