Reference

HTTP status code hub

Status codes tell you what kind of outcome you got—not always why. Use this hub for quick orientation, then jump into Fix an error when you have a real message to untangle.

• 200OK

  The request succeeded. Browsers and APIs use this for normal responses.

• 301Moved Permanently

  The resource has a new permanent URL. SEO value usually transfers to the target.

• 302Found

  Temporary redirect. Clients should keep using the original URL for future requests.

• 304Not Modified

  Cached copy is still valid—great for performance when validators match.

• 400Bad Request

  The server can’t parse the request—often malformed JSON, headers, or query params.

• 401Unauthorized

  Authentication is required or failed. Not the same as authorization (see 403).

• 403Forbidden

  Authenticated or not, this identity isn’t allowed to access the resource.

• 404Not Found

  No resource matches the URL. Often a routing or deployment issue.

• 405Method Not Allowed

  The verb (GET/POST/…) isn’t supported for this path.

• 408Request Timeout

  The server gave up waiting—often slow upstreams or network issues.

• 409Conflict

  The request conflicts with the current state—common in optimistic concurrency.

• 429Too Many Requests

  Rate limited. Slow down, add backoff, or raise limits with your provider.

• 500Internal Server Error

  Something broke on the server. Check logs, exceptions, and dependencies.

• 502Bad Gateway

  A proxy or edge server got an invalid response from an upstream server.

• 503Service Unavailable

  Temporary overload or maintenance. Often paired with Retry-After.

• 504Gateway Timeout

  A proxy timed out waiting for an upstream—common with cold starts or slow DB.