Check the security headers of a response
Copy the headers from the network panel, paste them here, and get the list a paid scanner gives you — plus the reason each header matters.
How HTTP Header Analyzer works
The request is made by your browser, so the answer is genuinely yours — your IP, your route, your speed. A server-side check would report the server's connection instead. That difference is the whole reason these pages exist.
That is the whole architecture: static files, one script, no upload endpoint to leak or log. Close the tab and the work is gone.
Good to know
- Works offline once loaded, including on flights and in locked-down networks.
- No file size limit beyond your device's own memory.
- Free to use, with no account and no usage counter.
- Results are produced locally, so they are not logged or shared with anyone.
Questions
Where do I get the headers?
Browser dev tools → Network → click the request → Response Headers, then copy them. Firefox and Chrome both let you copy the whole block.
Does it fetch my site?
No. A browser cannot read another origin's headers, and a proxy would mean sending your URL to a third party. Pasting is the honest route.
What counts as a weak header?
For example an HSTS max-age under a million seconds, or a CSP that still contains unsafe-inline. Present is not the same as useful.
Is a missing header a vulnerability?
Not by itself. It is a missing layer of defence — the site may be safe without it, but one bug becomes more expensive.
Keep going
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