Free online security tools that actually work
A free MxToolbox and DNSChecker.org alternative for engineers and IT teams. Every tool runs in your browser — no data leaves your device, no account required, no daily query caps.
DMARC & SPF Checker
Check any domain's SPF, DMARC, and DKIM records. See what's configured, what's missing, and what spoofers can exploit.
DNS Lookup
Look up A, AAAA, MX, NS, TXT, and CNAME records for any domain. Fast, accurate, no signup. Powered by Cloudflare 1.1.1.1.
Subdomain Finder
Discover every subdomain a domain has ever issued a certificate for. Powered by Certificate Transparency logs — a free Sublist3r alternative.
Built the way security tools should be
Nothing leaves your browser
Every check runs client-side. We never see what domain you queried.
Instant results
Direct queries to Cloudflare 1.1.1.1 — no waiting, no signup, no captcha.
Built by security engineers
The same checks our scanners run continuously, in a one-shot tool.
More tools coming soon — SSL checker, port-scan preview, security headers audit.
Secure your entire stack today
Start scanning in under 5 minutes. No credit card required. 14-day free trial included.