Public web diagnostics

Small, private-by-default utilities for practical checks.

Inspect public A, AAAA, MX, NS, TXT, CNAME and SOA records.

Review a public HTTPS certificate and its expiry date.

Read public domain registration information through RDAP.

Find a domain public SPF sender policy.

Inspect a public DKIM key for a mail selector.

Inspect the policy used for failed email alignment.

Check a public IPv4 address against bounded DNS lists.

Follow a short public HTTP redirect chain safely.

Inspect bounded response headers for a public URL.

Measure public response time, TTFB and page weight.