What this tool does
It checks certificate validity dates, issuer, trust status, Subject Alternative Names, key details, and chain depth for the public HTTPS endpoint.
SSL Checker
SSL Certificate Checker
Instantly check SSL certificate details, expiry date, issuer, and trust status for any domain.
Enter a domain or subdomain — e.g. underhost.com
Expiry & days remaining
Issuer & authority
Subject Alt Names
Trust chain status
What this tool checks
Enter any domain above to run a free SSL certificate check.
Expiry Date
See exactly when the certificate expires and how many days remain before renewal is needed.
Issuer & Authority
Identify who issued the certificate — Let's Encrypt, Sectigo, DigiCert, or any other CA.
SANs Coverage
View all domains and subdomains covered by the certificate via Subject Alternative Names.
Trust Status
Check whether the certificate is trusted by the system CA store or is self-signed.
Key Strength
Check the key type (RSA/ECDSA) and bit length to confirm modern cryptographic standards.
Chain Depth
Inspect how many certificates make up the chain, including intermediate CA certificates.
Need SSL for your hosting?
UnderHost includes free SSL certificates with all hosting plans. Get started in minutes.
Tool guide
How to use the SSL Certificate Checker
This tool inspects the public TLS certificate served by a domain so you can confirm HTTPS is trusted, current, and valid for the hostname visitors use.
Who it helps
- Website owners confirming HTTPS after launch or migration
- Developers checking staging or production certificates
- Hosting users troubleshooting browser SSL warnings
Usage instructions
Enter a domain such as example.com. The checker connects to port 443, reads the certificate, and reports the important trust and expiry signals.
Understanding the output
Warnings about expiry, trust, SAN coverage, or a weak chain should be treated as action items. An expiring certificate should be renewed before visitors see browser warnings.
Why it matters for hosting
SSL health is central to hosting, SEO, forms, checkout pages, and customer trust. UnderHost customers can use this check after DNS changes, migrations, or certificate renewals.
