HTTP Status Codes Cheat Sheet
Every HTTP status code you need to know, organized by class. A quick visual reference for developers, sysadmins, and anyone working with web APIs.
Status Code Classes
1xxInformational — The server has received the request headers and the client should proceed. These are provisional responses before the final answer.
2xxSuccess — The request was received, understood, and accepted. The action requested by the client was completed successfully.
3xxRedirection — The client must take additional action to complete the request, usually following a different URL provided in the response.
4xxClient Error — The request contains bad syntax or cannot be fulfilled. The problem is on the client side and the request should be corrected before retrying.
5xxServer Error — The server failed to fulfill a valid request. The problem is on the server side and the client may retry later.
Most Common in Practice
These are the status codes developers encounter most often when building and consuming APIs:
200 Standard success response
201 Resource created (POST success)
301 Permanent URL redirect (SEO)
302 Temporary redirect (login flows)
400 Invalid request data
401 Missing or invalid credentials
403 Insufficient permissions
404 Resource not found
500 Unhandled server exception
Learn More About HTTP
Understand the protocol behind these status codes, including request methods, headers, and how HTTPS secures the connection.