Free domain security tools
No signup, no email, no limits worth mentioning. Each one runs the same engine our customers use and shows you the exact fix for anything it finds.
DMARC checker
Enter a domain and we will read its DMARC record, tell you whether it is actually enforcing, and show you exactly what to publish if it is not.
Open the tool →SPF record checker
We resolve the full SPF record, follow every <code>include:</code> and <code>redirect=</code>, and count the DNS lookups it actually costs.
Open the tool →SSL certificate checker
We make one TLS connection, read the certificate, and check expiry, trust, hostname coverage and protocol support.
Open the tool →Security headers checker
We fetch the site once and inspect the response headers that control how browsers protect your visitors.
Open the tool →Want everything at once?
The full scan covers all of these plus DNS, subdomain takeover and exposed surface, in one report.
Run a full scan