SSL Certificate Checker | HTTPS Expiry and Issuer
Check a domain's SSL certificate issuer, subject, validity dates, expiry status, serial number, and HTTPS certificate details.
What the SSL Certificate Checker Reviews
The SSL certificate checker reviews a domain's HTTPS certificate details, including issuer, subject, serial number, validity dates, and expiry status.
Why Certificate Expiry Matters
Expired or misconfigured certificates can break HTTPS, trigger browser warnings, interrupt checkout flows, and reduce trust. Check before migrations, renewals, and DNS changes.
When to Recheck SSL
Recheck SSL after changing hosting, CDN, Cloudflare, Plesk, reverse proxies, domain aliases, or certificate providers. Certificate propagation can differ by hostname.
About This Tool
SSL Certificate Checker retrieves the TLS certificate for any domain and shows the issuer, validity period, expiry date, subject alternative names, and whether the certificate chain is complete. It helps you verify certificate health without installing any software.
When to Use It
Use this before going live with a domain to confirm the certificate is valid, when a browser shows a security warning and you want to diagnose the cause, or when monitoring certificates that are approaching their expiry date.
How to Use
- Enter the domain name you want to check.
- Click Check to retrieve the certificate details.
- Review the expiry date, issuer, and coverage of subdomains.
- Note any warnings about chain issues or mismatched names.
Frequently Asked Questions
How long before expiry should I renew an SSL certificate?
Renew at least 30 days before expiry to allow time for the process to complete without service interruption. Many services renew automatically 60 days before expiry.
What is a wildcard certificate?
A wildcard certificate covers a domain and all its immediate subdomains using an asterisk, for example *.example.com covers shop.example.com and blog.example.com.
Why does my certificate show as untrusted despite being valid?
An untrusted certificate typically means the issuing certificate authority is not in the browser's trust store, or the certificate chain is incomplete.