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HTTP Status Codes

Complete reference of all HTTP response status codes. Browse by category, search by code number or name.

1xx Informational

100

Continue

The server has received the request headers and the client should proceed to send the request body.

Usage: Used with Expect: 100-continue header for large uploads.

101

Switching Protocols

The server is switching to a different protocol as requested by the client.

Usage: WebSocket upgrades from HTTP.

102

Processing

The server has received and is processing the request, but no response is available yet.

Usage: WebDAV long-running operations.

103

Early Hints

Used to return some response headers before the final HTTP message.

Usage: Preloading resources while the server prepares the response.

2xx Success

200

OK

The request has succeeded.

Usage: Standard response for successful GET, POST, PUT requests.

201

Created

The request has been fulfilled and a new resource has been created.

Usage: Response after successful POST that creates a resource.

202

Accepted

The request has been accepted for processing, but the processing is not complete.

Usage: Asynchronous operations, job queues.

203

Non-Authoritative Information

The returned meta-information is from a local or third-party copy.

Usage: Proxy responses with modified headers.

204

No Content

The server has fulfilled the request but there is no content to return.

Usage: Successful DELETE, or PUT with no body to return.

205

Reset Content

The server has fulfilled the request and the client should reset the document view.

Usage: After form submission to clear the form.

206

Partial Content

The server is delivering only part of the resource due to a range header.

Usage: Video streaming, resumable downloads with Range header.

207

Multi-Status

Conveys information about multiple resources where multiple status codes might be appropriate.

Usage: WebDAV batch operations.

208

Already Reported

The members of a DAV binding have already been enumerated and are not included again.

Usage: WebDAV to avoid enumerating internal members repeatedly.

226

IM Used

The server has fulfilled a GET request with instance-manipulations applied.

Usage: Delta encoding responses.

3xx Redirection

300

Multiple Choices

The request has more than one possible response.

Usage: Content negotiation when multiple formats are available.

301

Moved Permanently

The resource has been permanently moved to a new URL.

Usage: SEO-friendly permanent URL redirects.

302

Found

The resource resides temporarily at a different URL.

Usage: Temporary redirects, login redirects.

303

See Other

The response can be found at a different URL using GET.

Usage: Redirect after POST to prevent resubmission.

304

Not Modified

The resource has not been modified since the last request.

Usage: Browser caching with If-Modified-Since or ETag.

305

Use Proxy

The requested resource must be accessed through a proxy.

Usage: Deprecated. Rarely used.

307

Temporary Redirect

The resource temporarily resides at a different URL. Method and body are not changed.

Usage: Like 302 but guarantees method is preserved.

308

Permanent Redirect

The resource has permanently moved. Method and body are not changed.

Usage: Like 301 but guarantees method is preserved.

4xx Client Errors

400

Bad Request

The server cannot process the request due to a client error.

Usage: Malformed syntax, invalid request parameters.

401

Unauthorized

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

Usage: Missing or invalid authentication credentials.

402

Payment Required

Reserved for future use. Intended for digital payment systems.

Usage: Paywalled content, API billing limits.

403

Forbidden

The server understood the request but refuses to authorize it.

Usage: Insufficient permissions, IP blocked.

404

Not Found

The requested resource could not be found on the server.

Usage: Missing page, deleted resource, wrong URL.

405

Method Not Allowed

The HTTP method is not supported for the requested resource.

Usage: POST to a read-only endpoint.

406

Not Acceptable

The server cannot produce a response matching the Accept headers.

Usage: Content negotiation failure.

407

Proxy Authentication Required

The client must first authenticate with the proxy.

Usage: Corporate proxy requiring credentials.

408

Request Timeout

The server timed out waiting for the request.

Usage: Slow client connections, idle timeouts.

409

Conflict

The request conflicts with the current state of the server.

Usage: Concurrent edits, duplicate resource creation.

410

Gone

The resource is no longer available and will not be available again.

Usage: Permanently deleted resources. Unlike 404, this is intentional.

411

Length Required

The server requires a Content-Length header.

Usage: Upload endpoints requiring size declaration.

412

Precondition Failed

A precondition given in the request headers was not met.

Usage: Conditional requests with If-Match or If-Unmodified-Since.

413

Payload Too Large

The request entity is larger than the server is willing to process.

Usage: File upload size limits.

414

URI Too Long

The URI provided was too long for the server to process.

Usage: Extremely long query strings.

415

Unsupported Media Type

The media format of the requested data is not supported.

Usage: Sending XML when only JSON is accepted.

416

Range Not Satisfiable

The range specified in the Range header cannot be fulfilled.

Usage: Invalid byte range for file downloads.

417

Expectation Failed

The expectation given in the Expect header could not be met.

Usage: Server cannot meet Expect: 100-continue.

418

I'm a Teapot

The server refuses to brew coffee because it is a teapot.

Usage: Easter egg from RFC 2324 (HTCPC). Used humorously.

421

Misdirected Request

The request was directed at a server that cannot produce a response.

Usage: HTTP/2 connection coalescing issues.

422

Unprocessable Entity

The request was well-formed but could not be followed due to semantic errors.

Usage: Validation errors in REST APIs.

423

Locked

The resource is currently locked.

Usage: WebDAV locked resources.

424

Failed Dependency

The request failed because it depended on another request that failed.

Usage: WebDAV batch operations.

425

Too Early

The server is unwilling to risk processing a request that might be replayed.

Usage: TLS early data (0-RTT) replay prevention.

426

Upgrade Required

The client should switch to a different protocol.

Usage: Server requires TLS or newer HTTP version.

428

Precondition Required

The origin server requires the request to be conditional.

Usage: Preventing lost updates without If-Match.

429

Too Many Requests

The user has sent too many requests in a given amount of time.

Usage: API rate limiting. Check Retry-After header.

431

Request Header Fields Too Large

The server refuses to process the request because headers are too large.

Usage: Oversized cookies or authorization tokens.

451

Unavailable For Legal Reasons

The resource is unavailable due to legal demands.

Usage: Government censorship, DMCA takedowns.

5xx Server Errors

500

Internal Server Error

The server encountered an unexpected condition that prevented it from fulfilling the request.

Usage: Unhandled exceptions, application crashes.

501

Not Implemented

The server does not support the functionality required to fulfill the request.

Usage: Unsupported HTTP methods.

502

Bad Gateway

The server received an invalid response from an upstream server.

Usage: Reverse proxy cannot reach the backend.

503

Service Unavailable

The server is not ready to handle the request.

Usage: Maintenance mode, overloaded servers.

504

Gateway Timeout

The server did not receive a timely response from an upstream server.

Usage: Backend server taking too long to respond.

505

HTTP Version Not Supported

The HTTP version used in the request is not supported.

Usage: Requesting with an unsupported HTTP version.

506

Variant Also Negotiates

Transparent content negotiation resulted in a circular reference.

Usage: Misconfigured content negotiation.

507

Insufficient Storage

The server cannot store the representation needed to complete the request.

Usage: WebDAV server out of disk space.

508

Loop Detected

The server detected an infinite loop while processing the request.

Usage: WebDAV recursive operations.

510

Not Extended

Further extensions to the request are required for the server to fulfill it.

Usage: HTTP Extension Framework requirements.

511

Network Authentication Required

The client needs to authenticate to gain network access.

Usage: Captive portals (Wi-Fi login pages).

Complete Reference

All standard HTTP status codes from 1xx informational to 5xx server errors, including WebDAV and modern extensions like 103 Early Hints.

Color Coded

Each category has a distinct color so you can quickly identify whether a code represents success, redirection, a client error or a server error.

Searchable

Instantly filter codes by number or name. Jump to any category with the navigation bar. Perfect for quick lookups during development.

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How to Use HTTP Status Codes Reference

The HTTP Status Codes Reference provides a comprehensive, searchable guide to all standard HTTP response codes with detailed explanations and practical examples. This browser-based tool is an essential desk reference for web developers, API designers, and DevOps engineers debugging request-response cycles and implementing proper error handling.

1

Open the HTTP Status Codes Reference

Navigate to the HTTP Status Codes Reference from the developer tools menu. The complete reference loads in your browser for instant access, even when working offline or without stable internet.

2

Browse by Category

Explore status codes organized by category: 1xx Informational, 2xx Success, 3xx Redirection, 4xx Client Error, and 5xx Server Error. Each category groups related codes for easy navigation and understanding.

3

Search for Specific Codes

Use the search function to quickly find a specific status code by number or keyword. Search for terms like 'not found,' 'redirect,' or 'unauthorized' to locate the relevant code instantly.

4

Read Detailed Explanations

Click on any status code to see its full description, common causes, appropriate usage scenarios, and practical examples of when and how to return that code in your API responses.

5

Apply to Your Projects

Use the reference to select the correct status codes for your API endpoints, error handlers, and middleware, ensuring your web application follows HTTP standards and best practices.

Common Use Cases

REST API Design

Select appropriate status codes for every API endpoint to communicate request outcomes clearly, helping client developers implement proper error handling and retry logic.

Debugging HTTP Errors

Quickly look up unfamiliar status codes encountered in browser developer tools, server logs, or API responses to understand and resolve issues efficiently.

API Documentation Writing

Reference correct status codes and their meanings when writing API documentation, ensuring your docs accurately describe possible response scenarios for each endpoint.

Error Handling Implementation

Implement comprehensive error handling in your web application by mapping business logic errors to semantically correct HTTP status codes for each failure scenario.

Pro Tips

  • -Use 201 Created instead of 200 OK when a POST request successfully creates a new resource, and include a Location header pointing to the new resource.
  • -Return 204 No Content for successful DELETE operations or PUT updates where no response body is needed, rather than returning an empty 200 response.
  • -Use 422 Unprocessable Entity for validation errors in API requests where the syntax is correct but the content fails business logic rules.
  • -Distinguish between 401 Unauthorized (missing or invalid authentication) and 403 Forbidden (authenticated but lacking permission) for clear API error responses.