HTTP status code lookup
Look up an HTTP status code such as 404 or 503 to see its name, what it means and when a server sends it.
- Runs in your browser
- No upload
- Result stays on your device
Privacy & limitsRuns in your browser. Nothing is uploaded.
Input content stays in this tab; Refentra does not upload or store it. Optional aggregate action counts are sent only with your usage consent. Clear the workspace when finished.
Supported profile: IANA status subset, checked 2026-10-07; RFC 9110 and extensions. A code alone does not diagnose a failure.
Maximum text: 200,000 UTF-16 units; parser limits can be smaller. Worker time limit: 15 seconds (regex 1.5 seconds).
Check the input and the result
- Prepare and choose the operation
Enter an HTTP status code and read its standard meaning and class before you investigate the actual request.
- Check a concrete example
Use this sample and compare the indicated result: 404 → Not Found, 4xx; 503 → Service Unavailable, 5xx
- Check the output before you reuse it
Compare the response body, the headers and your application logs separately. A generic status code can't explain the root cause on its own.
Answers for this task
Does 404 prove the server is offline?
No. It means the requested resource was not found. A connection failure and an HTTP error response are different things.
What should I check if the input fails?
Use a listed three-digit code, not a URL or a whole status line. An unknown code may be outside the curated table.
Where does this tool stop?
This is a local reference subset based on IANA. It is not an endpoint monitor, an uptime check or a live diagnosis of a server.