HTTP Status Codes Quick Reference: 200 to 500
The first digit indicates the class: 2xx success, 3xx redirect, 4xx client error, 5xx server error. 1xx are intermediate states.
Most common
- 200 OK: success
- 301/302: redirect
- 400: bad request format
- 401/403: unauthorized / forbidden
- 404: not found
- 500: server crashed
Debugging approach
See a 4xx? Check the request (params, token) first. A 5xx is a backend issue — check server logs.
💡 FreeToolset's status code tool supports search by code or keyword — handy when troubleshooting.