Seeing a 404?
Check the URL for typos. Verify the resource exists on the server. For SPAs, ensure your server is configured to serve index.html for client-side routes.
HTTP Status Codes Explained
Stop guessing what that status code means. Look it up, understand the problem, and fix it faster.
Complete Status Code Reference
Every standard HTTP status code, organized by category. Click any card to expand details and troubleshooting tips.
No status codes match your search. Try a different keyword or clear the filter.
Quick Troubleshooting Guide
500 Internal Server Error?
Look at your server logs first. Common causes: syntax errors in .htaccess, exhausted PHP memory limit, or a crashed backend process. Restart the service and check recent deployments.
401 vs 403?
A 401 Unauthorized means you need to log in (missing or invalid credentials). A 403 Forbidden means you are authenticated but don't have permission to access that resource.
API returning 429?
You're being rate-limited. Check the Retry-After header for how long to wait. Implement exponential backoff in your client.
Developer Notes
HTTP status codes are defined in RFC 7231 and related RFCs. The first digit of the code defines the class of response. Custom or non-standard codes (like 418 I'm a teapot) exist for fun or internal use but should be used sparingly in production APIs.
When designing REST APIs, choose the most specific status code available. For example, prefer 201 Created over 200 OK when a resource is successfully created. Always include a meaningful response body with error details for 4xx and 5xx responses.