SSL Certificate Checker
Check SSL certificate details for any domain. Verify expiry, issuer, and validity.
Why Check SSL?
Expired SSL certificates cause browser warnings, lost traffic, and security vulnerabilities. Regular checks prevent unexpected downtime.
What We Check
Certificate validity, issuer details, expiry date, days remaining, subject alternative names, and SHA-256 fingerprint.
What Is an SSL Certificate Checker?
An SSL certificate checker is a tool that inspects the SSL/TLS certificate installed on a web server and reports its validity, issuer, expiration date, and other critical details. SSL certificates are essential for establishing encrypted connections between clients and servers. If a certificate expires, is misconfigured, or is issued by an untrusted authority, browsers will display security warnings that drive visitors away and damage your reputation.
Our SSL Certificate Checker connects directly to your server and retrieves the certificate in real time. It validates the certificate chain, checks the expiration date, confirms the issuer, and displays the Subject Alternative Names (SANs) that define which domains the certificate covers. The tool also shows the SHA-256 fingerprint, which is useful for verifying certificate integrity and detecting unauthorized modifications.
How to Check an SSL Certificate
Enter the domain name of the server you want to check in the input field above. You do not need to include "https://" or any path - just the domain name like "example.com". Click "Check SSL", and the tool will establish a secure connection to your server and retrieve the certificate. Results appear within seconds, showing whether the certificate is valid or expired, along with all technical details.
Pay close attention to the "Days Remaining" counter, which tells you exactly how many days until your certificate expires. Industry best practice is to renew certificates at least 30 days before expiration. The SANs field is especially important if you use a multi-domain or wildcard certificate, as it confirms all your domains are properly covered.
Why Regular SSL Checks Are Important
Expired or misconfigured SSL certificates are one of the most common causes of website and API downtime. Browsers and HTTP clients enforce strict certificate validation, and a single expired certificate can render your entire service inaccessible. Automated monitoring of SSL certificates helps you catch expirations before they cause outages. Combine SSL checking with API uptime monitoring for comprehensive coverage of your infrastructure security and availability.