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DevOps Cheatsheets

Quick-reference cards for everyday developer and network operations. Searchable, filterable, and always available offline after first visit.

1xx — Informational

100

Continue

Server received request headers; client should proceed.

101

Switching Protocols

Server agrees to switch protocols (e.g., HTTP → WebSocket).

102

Processing

Server has received and is processing (WebDAV).

103

Early Hints

Used to preload resources while server prepares response.

2xx — Success

200

OK

Standard success response.

201

Created

Resource successfully created. Typically after POST.

202

Accepted

Request accepted but not yet completed (async).

204

No Content

Success with no response body (DELETE operations).

206

Partial Content

Partial GET response (Range requests).

3xx — Redirection

301

Moved Permanently

Resource has permanently moved to new URI.

302

Found

Temporary redirect (legacy).

304

Not Modified

Client cache is still valid; use cached version.

307

Temporary Redirect

Temporary redirect, preserves HTTP method.

308

Permanent Redirect

Permanent redirect, preserves HTTP method.

4xx — Client Errors

400

Bad Request

Malformed syntax or invalid request message.

401

Unauthorized

Authentication required.

403

Forbidden

Authenticated but not authorized.

404

Not Found

Resource does not exist.

405

Method Not Allowed

HTTP method not supported for this endpoint.

408

Request Timeout

Server timed out waiting for request.

409

Conflict

State conflict (e.g., duplicate resource).

410

Gone

Resource permanently deleted.

413

Payload Too Large

Request body exceeds server limit.

415

Unsupported Media Type

Content-Type not supported.

422

Unprocessable Entity

Validation errors (WebDAV/REST APIs).

429

Too Many Requests

Rate limit exceeded.

5xx — Server Errors

500

Internal Server Error

Generic server-side error.

501

Not Implemented

Server does not support the request feature.

502

Bad Gateway

Upstream server returned invalid response.

503

Service Unavailable

Server temporarily unable to handle requests.

504

Gateway Timeout

Upstream server timed out.

508

Loop Detected

Infinite loop detected (WebDAV).

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