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.
I built this because I kept finding out about my own broken sites the embarrassing way — a customer telling me, or a browser warning showing up mid-demo.
Two honest notes. First, automated accessibility checking only catches about a third of WCAG issues (the most common third: missing alt text, unlabeled form fields, empty icon buttons, blocked pinch-zoom). I say that in the product instead of pretending a scan proves ADA compliance, and I deliberately don't sell an overlay widget — sites using those still get sued.
Second, right after I shipped the accessibility check I pointed it at my own marketing site. It immediately found that 21 of my own pages had a search input with a placeholder and no label — the exact failure I'd just built detection for. Fixed now, but a good reminder that this stuff regresses silently on everyone.
Would love to hear what it should check next.