Wildcard DNS Checker
Detect whether a zone answers every subdomain with the same address — a wildcard (*) record. We resolve three random, never-registered subdomains and compare the answers.
Ready to Analyze
Enter a target value above or click any sample preset chip to generate real-time diagnostic output.
About the Wildcard DNS Checker
The Wildcard DNS Checker detects whether a zone has a wildcard record (`*.example.com`) by resolving three randomly-generated subdomains that could not possibly be registered by hand, then comparing the answers. If every random subdomain returns the same address or CNAME, the zone has a wildcard rule that catches every request.
Wildcards are legitimate — SaaS platforms, hosting providers and CDNs use them to route customer subdomains to a shared front door. But wildcards can also mask misconfiguration: a subdomain finder or SEO crawler may see thousands of 'live' subdomains that all point at the same 404 page. Security-wise, wildcard MX or wildcard A can turn typos into successful phishing landings.
Use Wildcard Checker before running our Subdomain Finder (to reason about the results correctly), when auditing a newly acquired domain, or when debugging a mysterious subdomain that resolves 'by accident'. Combine with the Propagation Checker to see how the wildcard replicates worldwide.
Enter the required value in the input field above (domain, IP, URL, or text depending on the tool).
Click the action button to run the check — results are computed instantly from our edge network.
Review the parsed output, key fields and any warnings shown in the result card.
Copy the result, share the page URL, or jump to a related tool from the sidebar to continue debugging.
- Three random probe subdomains — guaranteed unregistered
- Compares A, AAAA and CNAME answers for consistency
- Shows the wildcard target when one is detected
- Fast, zero setup, over DoH