Replit
Missing security headers on a Replit app
A Replit deployment is an ordinary website. The page, its same-origin scripts, and the headers from that host are what a visitor receives, and what this scan reads.
Headers the document response already sends, or does not send.
What the scan can see
Content-Security-Policy, Strict-Transport-Security on HTTPS, X-Content-Type-Options, framing protection via X-Frame-Options or CSP frame-ancestors, and Referrer-Policy. A missing Permissions-Policy is informational and does not drop the letter by itself. Either framing control is enough.
What it does not do
The scan does not score how strict a CSP is beyond whether it exists and whether frame-ancestors is set. A header that exists only on an API route we never request is not graded.
The Replit API, the workspace, and secrets that exist only in Replit's server environment are outside the fetch.
What to do next
Add the missing headers on the host, redeploy, and scan again. Turn HSTS on only after HTTP already redirects to HTTPS.
Questions
Does this open my Replit project?
No. The Replit API, the workspace, and secrets that exist only in Replit's server environment are outside the fetch.
Can the scan prove missing security headers is fully fixed?
The scan does not score how strict a CSP is beyond whether it exists and whether frame-ancestors is set. A header that exists only on an API route we never request is not graded.
What should I do if the scan finds it?
Add the missing headers on the host, redeploy, and scan again. Turn HSTS on only after HTTP already redirects to HTTPS.
Scan a URL you own
The same free check as the homepage. You confirm the app is yours before it runs.