Free tools

Security and network checks you can use right now, no signup required. Each one attacks a specific problem; the domain analyzer brings them all together.

Visitor snapshots

What Is My IP?

Your public IP address, reverse DNS, and the provider behind it.

IPv6 Test

Check whether your connection and browser have native IPv6 and Dual-Stack support.

Site status

Domain Analyzer

DNS, TLS, headers, email, ports and more — your domain's full report in a minute.

Perimeter VPS Analyzer

10-second external diagnostic for SSL certificates, DNS records, SPF, DMARC, and perimeter ports of your VPS.

Redirect Trace

Follow the full redirect chain of any URL, hop by hop.

Is It Down

Check if a domain responds from our server right now.

Domain & DNS

DNS Propagation

Query a record against 6 public resolvers at once and spot disagreements.

DNSSEC Checker

Check whether your domain has DNSSEC enabled and validated.

CAA Generator

Generate the right CAA record and check whether you already have one.

Email

SPF/DMARC Generator

Generate the exact TXT records to protect your domain against email spoofing.

Email Header Analyzer

Paste email headers and check SPF, DKIM, DMARC and spoofing. Entirely in your browser.

DKIM Checker

Find and validate your DKIM keys by trying the common selectors.

Server & DevOps

VPS Hardening Generator

Downloadable bash script to secure a new VPS: firewall, fail2ban, hardened SSH.

sshd_config Generator

Hardened SSH directives with an explanation for each one.

Fail2ban Jail Generator

Jail ready to paste into jail.local for SSH, Nginx, Postfix, or Dovecot.

Passwords & credentials

Password Breach Checker

Check if your password has appeared in a breach, without it ever leaving your browser.

Has my email been leaked?

Check if your email address has appeared in a known data breach.