The previous numerical comparison has been removed because its measurement records were unavailable. The tests below describe how to compare DNS tools; they are not vendor scores.
Make the resolver part of the input
Comparing two DNS tools without knowing their resolver is like comparing two requests without knowing the destination. Record the hostname, record type, resolver and observation time. Your local resolver and a public resolver can return different cached answers without either tool displaying them incorrectly.
Use fixtures with known answers
On a domain you control, prepare a hostname with an A record, one with a CNAME, and a name that does not exist. Keep a record of your zone configuration and use a test zone so you do not interfere with production. If the tool offers several resolvers, use the same selection for each repeated comparison.
- Does the tool distinguish NXDOMAIN from NOERROR with no record of the requested type?
- Can it show a CNAME chain without presenting the alias as an address?
- Are TTL values and the queried record types visible?
- Does a failed resolver request appear as a transport error, rather than a fabricated empty answer?
- Can you export or copy the full response with its query details?
Compare with raw output
dig @1.1.1.1 example.com A
dig @8.8.8.8 example.com A
dig @8.8.8.8 example.com AAAAThe commands use a documentation domain to demonstrate the shape of the test. For controlled expected answers, substitute your test domain. A missing AAAA answer alone should not be scored as a failure if the name intentionally supports only IPv4.
Choose the detail you need
For a support request, visible resolver identity and reproducible answers may be sufficient. For delegation problems, you also need authoritative-server and trace information. For an ongoing incident, keep dated observations rather than relying on a tool’s current screen.
Try the WebsiteDown DNS lookup with those tasks, then compare it with raw resolver output. We operate that tool, so this page is not an independent recommendation. The DNS troubleshooting guide explains the next step when answers disagree.