About the HTTP Status Codes
HTTP status codes carry more meaning than most APIs use. The difference between a 301 and a 302 determines whether ranking signals transfer; the difference between 401 and 403 is authentication versus authorisation. This searchable reference covers every standard code with its practical implications.
How to use the HTTP Status Codes
- Search by code number or by keyword.
- Filter by class — 2xx success, 3xx redirect, 4xx client error, 5xx server error.
- Read the meaning and the typical cause.
- Check the SEO note on the redirect and error codes that affect indexing.
Frequently asked questions
What is the difference between a 301 and a 302 redirect?
301 is permanent and passes ranking signals to the new URL; 302 is temporary and tells search engines to keep the original indexed. Using 302 for a permanent move is a common and costly mistake.
When should I return 404 rather than 410?
404 means not found, possibly temporarily. 410 means deliberately and permanently gone, and search engines typically drop a 410 URL from the index faster.
What is a soft 404?
A page that says "not found" to the user but returns HTTP 200. Search engines index it as a real page, which wastes crawl budget. Single-page applications produce these very easily.
What is the difference between 401 and 403?
401 means you have not authenticated, so credentials might help. 403 means you are authenticated but not allowed, so retrying with the same identity will not.