HTTP Status Codes
HTTP code reference
HTTP Status Codes: HTTP code reference. A free, browser-based tool from DevToolbox that runs entirely on your own device: no upload, no account, no tracking.
About the HTTP Status Codes
Look up an HTTP status code and get its reason phrase, its class and what it actually implies for caching and retries.
This is a reference and calculation tool, not a probe: the numbers and lookups are computed from tables and arithmetic in your browser rather than by contacting any host. That keeps it usable behind a firewall and means nothing about your network is disclosed.
What you can do with it
- HTTP response codes
- Status code reference
- HTTP codes list
- REST status codes
How to use it
- Enter the address, code or identifier you want to look up.
- The breakdown is calculated locally from reference tables and arithmetic.
- Every derived field is shown together so you can check your working.
- Copy the result or share the link.
Questions
- When should I use 401 rather than 403?
- 401 means the request was not authenticated and a valid credential might succeed, and it must come with a WWW-Authenticate header. 403 means the server knows who you are and is refusing anyway, so retrying with the same credential will not help.
- Is my data uploaded anywhere?
- No. The tool is JavaScript that runs in the tab you already have open, and DevToolbox has no backend to send anything to. You can open the network tab and watch: after the page and its script load, nothing is sent while you work.
Related tools
The HTTP Status Codes sits in Network & API, one of the 90 tools on DevToolbox.