Free tools
Check your server's security in seconds
Quick, free checks for websites and Linux servers. No sign-up, no tracking, and the config tools never upload your files.
Security headers checker
Grade a site's HTTP security headers: CSP, HSTS, framing, referrer and cookies.
TLS / SSL certificate checker
Check certificate expiry, chain trust, hostname match and old TLS versions.
SSH server checker
Audit an SSH server's key exchange, ciphers and MACs, and test for Terrapin.
sshd_config checker
Paste your sshd_config and get a Hardline-style hardening report. Runs in your browser.
CSP builder
Build or tighten a Content-Security-Policy and copy it for nginx, Apache or a meta tag.
Email security checker (SPF, DKIM, DMARC)
Check a domain's SPF, DKIM, DMARC, MTA-STS and TLS-RPT records and see who can spoof it.
DNS & DNSSEC checker
Look up A, AAAA, MX, NS, TXT and CAA records and test whether DNSSEC validates.
Open port checker
See which ports on your own connection are reachable from the internet, like SSH, RDP or databases.
Password & passphrase generator
Make strong random passwords or memorable diceware passphrases. Generated in your browser, never sent anywhere.