HTTP Status Code Lookup Web & SEO
Look up what any HTTP status code means and when to use it.
HTTP Status Code Lookup is a free online tool that look up what any HTTP status code means and when to use it. It runs entirely in your web browser using plain JavaScript, so files are processed on your own device and never uploaded to a server. There is no sign-up, no file size limit imposed by the site, no watermark and no paid tier.
- Price
- Free — no account, no quota, no watermark
- Category
- Web & SEO
- Where it runs
- In your browser, on your device
- Files uploaded
- None
- Technology
- plain JavaScript
- Settings
- None — it just works
- Works offline
- Yes, after the first visit
About HTTP Status Code Lookup
Status codes are grouped by class, and the class is the part that carries meaning: 2xx succeeded, 3xx means look elsewhere, 4xx is the client's fault, 5xx is the server's. The definitions here follow RFC 9110, which replaced the older RFC 7231 in 2022. The distinctions that cause the most real confusion — 301 versus 308, 401 versus 403 — are called out explicitly.
How to use it
- Paste the text you want to run through http status code lookup.
- There is nothing to configure — the result updates as you type.
Under the hood
| Runs on | plain JavaScript — runs the whole thing |
Questions
What is the difference between 401 and 403?
401 Unauthorized means "I do not know who you are" and must include a WWW-Authenticate header — authenticating may help. 403 Forbidden means "I know who you are and you still may not" — authenticating again will not help.
Should I use 301 or 308 for a redirect?
308 preserves the request method; 301 historically allowed clients to convert a POST to a GET, and many still do. For a permanent move where the method matters, 308 is correct. For a plain page move, 301 is universally understood.