What it reads
The landing page's cross-origin (CORS) behaviour, its allowed HTTP methods, and whether its Content-Security-Policy, where it has one, includes frame-ancestors.
Check 31 of 54 · Web and TLS
App-layer headers, explained.
A deeper web setting that could let another site read your users' data.
Engine 1.57.0, read 25 October 2026
Free checkScoredReliability: High
Is your website set up safely?
What the check does, and where it stops.
Why it matters
One wrong cross-origin setting lets any website read your pages as the signed-in visitor.
What a failure looks like
A failure is a finding in your result. The check is scored, so it can lower your score, and the Full Report gives every finding its severity and a fix. If the check cannot finish, it is recorded as unknown: it carries no penalty, and it is never a pass.
Where its limits are
Landing page only. If the method probe cannot finish, the result says so and grades the rest.
ReliabilityHigh: narrow, known blind spots
Check 31 is one of 15 in Web and TLS. See it in its row on the scanner page, beside the rest of Web and TLS.
See how your domain does.
The free check includes this one and takes about 30 seconds. No account. Nothing to install.