SSL Certificate Checker
Check SSL certificate status, expiry and issuer for any domain.
Enter a domain to check its SSL certificate
e.g. google.com, github.com
Check SSL/TLS certificate details for any domain by querying Certificate Transparency logs — see certificate authority, validity dates, SANs, and expiry countdown without installing anything.
Key Features
Certificate Transparency Lookup
Queries crt.sh CT log aggregator to find all publicly logged certificates for a domain, including current and historical records.
Expiry Countdown
Shows the number of days until the certificate expires with colour-coded status: green (healthy), amber (expiring soon <30 days), red (expired).
Subject Alternative Names
Lists all SANs covered by the certificate — useful for verifying wildcard coverage and multi-domain certificates.
Issuer & CA Details
Displays the Certificate Authority, issuer common name, and certificate serial number.
All Certificates History
Toggle to view all historically logged certificates for the domain, not just the most recent, for audit and chain validation.
Data Source Transparency
Clearly discloses that data comes from crt.sh Certificate Transparency logs — not a live TLS handshake.
How to Use
- 1Enter a domain name (e.g., example.com) in the input field — no https:// prefix needed.
- 2Click Check SSL to query Certificate Transparency logs.
- 3Review the certificate summary: CN, issuer, validity range, days until expiry, and SANs.
- 4Check the colour-coded expiry status: green = valid, amber = expiring within 30 days, red = expired.
- 5Toggle "Show all certificates" to view the full certificate history for the domain.