Perimeter

What it does

Most website problems stay invisible until they cost you: a certificate quietly expires because auto-renewal broke, a deploy drops a security header, a redesign ships images with no alt text. Perimeter checks four things in one scan and grades them — TLS certificate, security headers, DNS/email auth (SPF/DMARC), and WCAG accessibility. Free, no signup. Paid plans re-check daily, alert you when something breaks, and show how to fix each finding. Compliance adds a dated, auditor-ready report.

Free instant check of your site

Free instant check of your TLS certificate , security headers , DNS/email authentication and accessibility (WCAG) — the four things a security or compliance review always flags. No signup. Checks the certificate expiry & chain, HSTS/CSP and other headers, DMARC/SPF/CAA, and common WCAG failures (missing alt text, unlabeled fields, zoom blocking). Read-only, from the outside — exactly what an attacker, auditor, or ADA plaintiff's lawyer sees. After the free check, Perimeter watches your domains every day — here's what you get inside. Certificates expire. A deploy drops a header. DNS gets edited. Perimeter re-checks every day and emails you the moment something regresses — before your…from perimeter.getunlogged.com

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