Domain, DNS and certificate checks
Inspect DNS/CNAME records, HTTP redirects and TLS certificates for a domain. Server-side observations and your browser connection are separate measurement points.
Using and interpreting this tool
Confirm the target and measurement point, then start the checks you need. Results retain sources, observation times and missing-data reasons. Traffic-intensive checks require a separate start.
After changing one setting, start a fresh run and compare A/B snapshots in history. Unknown, unconfigured and inapplicable do not mean passed.
Related tools and guides
Live measurements run in your browser after JavaScript loads. This introduction contains no visitor detection results.