Debugging Reference

HTTP Status Codes Errors

13 common HTTP Status Codes errors with verified solutions.

400 Bad Request

The server cannot process the request due to malformed syntax, invalid parameters, or bad encoding.

medium

401 Unauthorized

The request requires authentication. The client must provide valid credentials.

high

403 Forbidden

The server understood the request but refuses to authorize it. Authentication won't help — the user lacks permissions.

high

404 Not Found

The server cannot find the requested resource. The URL may be wrong, the resource may have been deleted, or the route doesn't exist.

medium

405 Method Not Allowed

The HTTP method (GET, POST, PUT, DELETE) is not supported for this endpoint.

medium

410 Gone

The resource existed but has been permanently removed. Unlike 404, this explicitly tells clients the resource won't come back.

low

415 Unsupported Media Type

The server refuses the request because the Content-Type is not supported.

low

422 Unprocessable Entity

The request was well-formed but the server cannot process it due to semantic errors (e.g., validation failures).

medium

429 Too Many Requests

The client has sent too many requests in a given time period. The server is rate-limiting to protect itself.

high

500 Internal Server Error

The server encountered an unexpected condition that prevented it from fulfilling the request.

critical

502 Bad Gateway

A proxy or gateway received an invalid response from an upstream server.

critical

503 Service Unavailable

The server is temporarily unable to handle the request, usually due to maintenance or overload.

critical

504 Gateway Timeout

A gateway or proxy did not receive a timely response from the upstream server.

critical