How healthy is your website?
Run the full 40-point Safety Check for a graded report, or a quick single check below. Every check is free, read-only and changes nothing on your site.
One question at a time.
SSL / TLS Checker
Check any website's SSL certificate, expiry, TLS 1.0/1.1, TLS 1.3, cipher strength, HSTS and mixed content. Free and instant.
Open the tool → Browser protectionSecurity Headers Checker
Check a website's security headers: Content-Security-Policy, HSTS, X-Frame-Options, nosniff, Referrer-Policy, Permissions-Policy, CORS and cookie flags.
Open the tool → Email securityDMARC, SPF & DKIM Checker
Check whether anyone can send email pretending to be your domain: SPF, DKIM, DMARC policy, MTA-STS and your mail servers' blacklist status.
Open the tool → ReputationIP & Domain Blacklist Checker
Check if your IP address, domain or mail servers are on Spamhaus, SpamCop, Barracuda, SORBS, SURBL, URIBL and other blacklists, plus Google Safe Browsing.
Open the tool → SoftwarePHP & Server Version Checker
Check which PHP, web server, CMS and JavaScript library versions a site announces, whether they are out of support, and which known vulnerabilities apply.
Open the tool → AI agentsAI Crawler & Bot Rules Checker
See whether your robots.txt sets rules for 20 AI crawlers such as GPTBot, ClaudeBot, PerplexityBot and Google-Extended, and whether anything enforces them.
Open the tool → Everything at onceFull Health Check
All of these and more: 40 checks, a grade, and exactly which gaps SENTRA closes.
Run the Safety Check →See SENTRA on your own traffic.
Book a walkthrough, or start with a free Safety Check of your site.