HTTPS · TLS · Certificate Validation

SSL Certificate Checker

Verify if any website has a valid SSL/TLS certificate. Check expiry date, certificate issuer, and HTTPS configuration — before your users see the dreaded "Not Secure" warning.

SSL Certificate Checker
Enter any domain to check its SSL certificate status, validity period, and issuer information.
Enter a domain → click Check SSL
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What is an SSL certificate?

An SSL (Secure Sockets Layer) certificate — more accurately called a TLS certificate today — is a digital certificate that authenticates a website's identity and enables encrypted connections. When a website has a valid SSL certificate, browsers show a padlock icon and use HTTPS instead of HTTP. Without it, browsers display a "Not Secure" warning that drives users away.

Why check SSL certificate expiry?

SSL certificates expire — typically after 90 days (Let's Encrypt) or 1-2 years (commercial CAs). An expired certificate causes browsers to block access to your site with a full-page warning, immediately destroying user trust. Developers and site owners should monitor certificate expiry proactively. This tool tells you exactly how many days remain before expiry.

What does this SSL checker verify?

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FAQ

SSL certificate questions

How do I fix an expired SSL certificate?
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If you use Let's Encrypt (via Certbot, GitHub Pages, Netlify, or Vercel), renewal is automatic — check if your renewal process is running. For commercial certificates, contact your certificate authority or hosting provider to renew. GitHub Pages automatically renews SSL for custom domains — if it's expired there, remove and re-add your custom domain in repository settings.
What is the difference between SSL and TLS?
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SSL (Secure Sockets Layer) is the older protocol, now deprecated. TLS (Transport Layer Security) is its modern replacement. Despite this, the industry still commonly uses "SSL" to refer to what is technically TLS. When you see "SSL certificate", it almost always means a TLS certificate. Current websites use TLS 1.2 or TLS 1.3.
Is a free SSL certificate (Let's Encrypt) as secure as a paid one?
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Yes, for encryption purposes. Let's Encrypt certificates provide the same level of encryption as paid certificates. The main difference is that paid certificates (like EV certificates) include additional identity verification and show the organization name in the browser bar. For most websites, Let's Encrypt is perfectly sufficient.
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