Domain Inspector

tst.dev/dns

Enter a domain to inspect its DNS records, email-authentication policy (SPF, DMARC, DKIM), and certificate history.

Resolver

Compare against the other resolver

Result

Enter a domain and choose a resolver, then click Lookup. Nothing is fetched until you do.

Certificates

Source: crt.sh — a third-party certificate-transparency index. Requests go directly from your browser to crt.sh.

Privacy

All tools run entirely in your browser. The Domain Inspector is the one exception to “zero network calls”: when you enter a domain and trigger a lookup, your browser queries a public DNS-over-HTTPS resolver (Cloudflare by default, Google as an alternative — your choice, shown in the UI) and, for the certificate section, crt.sh’s public certificate-transparency index. These requests go directly from your browser to those services — tst.dev servers never see them, and nothing is logged by us. No lookup happens unless you start one.