Multi-Domain Cert Checker

Check multi-domain SAN certificate coverage

About Multi-Domain Cert Checker

Our Multi-Domain Cert Checker validates SSL/TLS certificate coverage for multiple domains using a single Subject Alternative Name (SAN) certificate. Enter a primary domain, and the tool checks which domains are covered by the SAN list. This is essential for managing multi-domain wildcard certificates and ensuring all your domains are properly secured.

How to Use

1Enter the primary domain you want to check.
2Click "Check" to fetch the certificate and SAN list.
3Review all SANs listed on the certificate.
4Verify that all your domains are covered by the SAN list.

Use Cases

•Verify SAN coverage for multi-domain certificates
•Check if all subdomains are covered by a wildcard cert
•Audit certificate renewal to ensure no domains are missed
•Validate load-balanced server certificates cover all services

Frequently Asked Questions

SAN certificates can cover up to 100+ domains depending on the CA. Common plans cover 3-25 domains.

A wildcard SAN (e.g., *.example.com) covers all subdomains of a domain in a single entry.

Enter each domain separated by a comma or newline to check multiple domains against the certificate.

The tool will flag domains not covered by the SAN list, so you can add them before the certificate expires.

Tips & Best Practices

•SAN certificates are more flexible than wildcard certificates for multiple domains
•Use multi-domain certificates to reduce certificate management overhead
•Ensure all domains in the SAN list are under your control
•Monitor all domains in the SAN list for expiry and security

Technical Details

SAN: Subject Alternative Name extension analysis
Types: DNS names, IP addresses, email addresses, URIs
Limit: Maximum 100 SAN entries per certificate
Validation: Domain ownership verification for each SAN entry