Free security tools for your website
Genuinely useful checks you can run right now — no account, no email wall, no lead-trap. Each one gives you a clear result and the exact fix. Built by the team behind Bug Circuit's human security audits.
Security Headers Checker
Grade your HTTP security headers A–F and get the exact line to fix each missing one.
Email Spoofing Checker
See whether criminals can send email that looks like it came from your domain (SPF, DKIM, DMARC).
SSL Certificate Checker
Check when your certificate expires, who issued it, and whether the chain and hostnames are actually valid.
DNS Record Lookup
Every A, AAAA, MX, NS, TXT and CNAME record for a domain, with the misconfigurations that matter flagged.
Subdomain Finder
Discover every subdomain of a domain from 10 passive OSINT sources, resolved live with CDN detection — the same engine behind our audits.
Website Technology Checker
Find out what a website is built with — CMS, framework, server, CDN and WAF — from a single request, plus its security-header posture.
Penetration Test Cost Calculator
Estimate what a penetration test should cost for your site, based on real 2026 market rates.
Data Breach Cost Calculator
Estimate what a breach would actually cost your business — downtime, recovery, notification and lost trade.
Looking for downloadable tools and templates instead? Those live in our free tools store. New online tools ship regularly — check back, or run the one that’s live now.