HTTP Cheatsheet

This site is a reference for the HyperText-Transfer Protocol (HTTP)

Last updated on 09 March, 2021 at 13:59:41 Optimized for

HTTP is the foundation for communication on the World Wide Web. The development of the protocol was initiated by Sir Tim Berners Lee in 1989 at CERN. Three version (HTTP/1. HTTP/2 and HTTP/3) exists. HTTP/1 is no longer widespread and adoption is moving towards HTTP/3 whereas HTTP/2 is virtually supported by all browsers at this point. HTTP/3 uses UDP instead of TCP for the underlying transport protocol. HTTP/3 is enabled by default on the latest MacOS releases and can be enabled in stable versions of Chrome and Firefox.

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1xx

Informational Responses

Command Description
100

Continue

101

Switching Protocols

102

Processing

2xx

Success Responses

Command Description
200

OK

201

Created

202

Accepted

203

Non-Authoritative Information

204

No Content

205

Reset Content

206

Partial Content

207

Multi-Status (WebDAV)

208

Already Reported (WebDAV)

226

IM Used

3xx

Redirection Responses

Command Description
300

Multiple Choices

301

Moved Permanently

302

Found

303

See Other

304

Not Modified

305

Use Proxy

306

(Unused)

307

Temporary Redirect

308

Permanent Redirect (experimental)

4xx

Client Error Responses

Command Description
400

Bad Request

401

Unauthorized

402

Payment Required

403

Forbidden

404

Not Found

405

Method Not Allowed

406

Not Acceptable

407

Proxy Authentication Required

408

Request Timeout

409

Conflict

410

Gone

411

Length Required

412

Precondition Failed

413

Request Entity Too Large

414

Request-URI Too Long

415

Unsupported Media Type

416

Requested Range Not Satisfiable

417

Expectation Failed

418

I'm a teapot (RFC 2324)

420

Enhance Your Calm (Twitter)

422

Unprocessable Entity (WebDAV)

423

Locked (WebDAV)

424

Failed Dependency (WebDAV)

425

Reserved for WebDAV

426

Upgrade Required

428

Precondition Required

429

Too Many Requests

431

Request Header Fields Too Large

444

No Response (Nginx)

449

Retry With (Microsoft)

450

Blocked by Windows Parental Controls (Microsoft)

451

Unavailable For Legal Reasons

499

Client Closed Request (Nginx)

5xx

Server Error Responses

Command Description
500

Internal Server Error

501

Not Implemented

502

Bad Gateway

503

Service Unavailable

504

Gateway Timeout

505

HTTP Version Not Supported

506

Variant Also Negotiates (Experimental)

507

Insufficient Storage (WebDAV)

508

Loop Detected (WebDAV)

509

Bandwidth Limit Exceeded (Apache)

510

Not Extended

511

Network Authentication Required

598

Network read timeout error

599

Network connect timeout error

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