Migrate a site
Link diagnostics
Updated September 2026
Diagnostics is a quick health check for one preview link. Use it when a preview shows an error or a blank page, before you dig into server logs.
On this page
Run diagnostics
Open Diagnostics in the sidebar, pick a link and run the checks. Nothing is changed on your server: DNSPeek only opens an HTTP and an HTTPS connection, the same way a preview does. Diagnostics does not count towards any plan quota.
What each check means
| Check | Meaning |
|---|---|
| Link Status | Fails when the link is switched off. |
| Target Domain | The domain DNSPeek asks the server for (the Host header). |
| Target IP | The server address the preview connects to. |
| Expiry | OK without an expiry, a warning while an expiry date is set, a failure once it has passed. |
| HTTP Check | Connects to the server on the link’s HTTP port and asks for your domain. A warning means the server did not answer as expected. |
| SSL Certificate | Connects on the link’s HTTPS port and checks whether the certificate is valid for your domain. |
Common fixes
- HTTP Check warns: the IP or port is wrong, a firewall blocks outside connections, or the web server has no site for this domain yet. See Find your server IP.
- SSL Certificate fails: normal before the DNS switch when the new host issues certificates only after DNS points at it. Set the link’s SSL mode to Skip verification or Auto for the preview.
- For a full crawl of every page, run a QA report.