The Status Codes That Matter

There are over 60 HTTP status codes, but you'll use about 15 of them regularly. Here are the ones every developer should know by heart.

2xx — Success

  • 200 OK — the request succeeded (most common response)
  • 201 Created — a new resource was created (use after POST)
  • 204 No Content — success but no body to return (common for DELETE)

3xx — Redirection

  • 301 Moved Permanently — the URL has changed forever (SEO-safe redirect)
  • 302 Found — temporary redirect (use sparingly)
  • 304 Not Modified — cached version is still valid (saves bandwidth)

4xx — Client Errors

  • 400 Bad Request — malformed request (invalid JSON, missing fields)
  • 401 Unauthorized — authentication required (no valid credentials)
  • 403 Forbidden — authenticated but not authorized
  • 404 Not Found — resource doesn't exist
  • 409 Conflict — request conflicts with current state (duplicate entry)
  • 422 Unprocessable Entity — valid syntax but semantic errors (validation failures)
  • 429 Too Many Requests — rate limited

5xx — Server Errors

  • 500 Internal Server Error — generic server failure
  • 502 Bad Gateway — upstream server returned invalid response
  • 503 Service Unavailable — server temporarily overloaded or in maintenance
  • 504 Gateway Timeout — upstream server didn't respond in time

Complete Reference

Use the HTTP Status Codes reference on CodeKitLab for the full list with descriptions, categories, and examples. Building an API? The cURL Command Builder lets you test endpoints and see status codes in practice. Need to document your API responses? The AI API Doc Generator helps you create formatted documentation.

Common Mistakes

  • Returning 200 for errors (always use appropriate error codes)
  • Using 404 when you mean 403 (don't hide resource existence unless intentional)
  • Returning 500 for validation errors (use 400 or 422)
  • Not setting proper status codes in APIs (many frameworks default to 200)

HTTP-statuskoder du bor kanna till

De viktigaste: 200 OK, 201 Created, 301 Redirect, 400 Bad Request, 401 Unauthorized, 404 Not Found, 500 Server Error. Fullstandig referens pa HTTP Status Codes. Testa med cURL Command Builder.

HTTP-Statuscodes die Sie kennen sollten

Die wichtigsten: 200 OK, 201 Created, 301 Redirect, 400 Bad Request, 401 Unauthorized, 404 Not Found, 500 Server Error. Vollstandige Referenz unter HTTP Status Codes. Testen Sie mit dem cURL Command Builder.

Codes HTTP a connaitre

Les essentiels : 200 OK, 201 Created, 301 Redirect, 400 Bad Request, 401 Unauthorized, 404 Not Found, 500 Server Error. Reference complete sur HTTP Status Codes. Testez avec le cURL Command Builder.

Codigos HTTP que debes conocer

Los esenciales: 200 OK, 201 Created, 301 Redirect, 400 Bad Request, 401 Unauthorized, 404 Not Found, 500 Server Error. Referencia completa en HTTP Status Codes. Prueba con el cURL Command Builder.

رموز حالة HTTP التي يجب معرفتها

الأساسية: 200 OK, 201 Created, 301 Redirect, 400 Bad Request, 401 Unauthorized, 404 Not Found, 500 Server Error. المرجع الكامل على HTTP Status Codes. اختبر باستخدام cURL Command Builder.

HTTP اسٹیٹس کوڈز جو آپ کو جاننے چاہئیں

اہم ترین: 200 OK, 201 Created, 301 Redirect, 400 Bad Request, 401 Unauthorized, 404 Not Found, 500 Server Error۔ مکمل حوالہ HTTP Status Codes پر۔ cURL Command Builder سے ٹیسٹ کریں۔