SAN Pattern Checker

Analyze Subject Alternative Name patterns

About SAN Pattern Checker

Our SAN Pattern Checker extracts and analyzes all Subject Alternative Names from an SSL certificate. It categorizes entries by type — DNS names, wildcard domains, and IP addresses — and identifies patterns in the SAN list. This is essential for understanding the full scope of domains a certificate covers and detecting potential gaps in coverage.

How to Use

1Enter the domain whose SAN patterns you want to analyze.
2Click "Check" to fetch and parse the certificate's SANs.
3Review the full list of DNS names, wildcards, and IPs.
4Identify patterns and check for any missing domains.

Use Cases

•Audit SAN coverage after certificate renewal
•Detect unexpected wildcard patterns in certificates
•Verify IP addresses are properly listed as SANs
•Catalog all domains protected by a multi-SAN certificate

Frequently Asked Questions

It detects DNS names, wildcard domains (*.example.com), and IP address SAN entries.

Wildcards are shown with the asterisk prefix (e.g., *.example.com) so you can see the domain scope.

Yes. The tool provides a count and breakdown of all SAN entries by type.

Overly broad wildcards or unexpected domain patterns may be flagged as potential security concerns.

Tips & Best Practices

•Analyze SAN patterns to understand certificate coverage across subdomains
•Use pattern analysis to identify certificate reuse or sharing
•Monitor SAN patterns for unauthorized domain additions
•Compare SAN patterns before and after certificate renewals

Technical Details

Analysis: Pattern matching and grouping of SAN entries
Patterns: Wildcard, specific domain, and IP address patterns
Grouping: Certificates grouped by common patterns
Export: Pattern analysis results in CSV and JSON formats