Free SSL Certificate Checker
Enter a domain to inspect its TLS certificate. We'll report the issuer, expiry date, and warn if the certificate is close to expiring.
What this SSL certificate checker checks
This free SSL certificate checker inspects the TLS certificate on the domain you enter and reports the issuer, the expiry date, and how many days remain until it needs renewing. An expired certificate throws a full-page browser warning that stops visitors in their tracks, so knowing your expiry date ahead of time is essential.
To check whether your pages actually load securely and are free of mixed content, use the HTTPS checker.
Why the certificate matters
Your TLS certificate is what makes the padlock appear and encrypts traffic between your visitors and your server. When it expires, browsers show an aggressive "your connection is not private" interstitial, and most visitors leave immediately rather than click through, so an expiry is effectively downtime for conversions.
Certificates are also time-limited by design: free automated certificates (such as Let's Encrypt) last 90 days and even paid ones are capped at about 13 months, so a certificate that is not auto-renewing will lapse surprisingly often. Checking the days remaining tells you whether renewal is handled or a deadline is creeping up. This tool warns when fewer than 30 days remain and fails at 7 days or less, so you get a clear signal well before visitors ever see a warning.
How to fix an expiring certificate
The fix is almost always to automate renewal so a human never has to remember it:
- Use a certificate authority with automated renewal (many hosts and CDNs issue and renew free certificates for you).
- If you run your own server, use a tool such as Certbot to auto-renew and reload the web server on renewal.
- If a certificate is close to expiry with no auto-renewal, renew it manually now and then set up automation so it does not recur.
- After renewing, confirm the new certificate is live and the chain is complete.
Honest limits
This tool reports the leaf certificate's issuer and expiry for the domain you enter; it does not perform a deep audit of the full trust chain or cipher configuration. Certificate expiry is one of the Quick Wins in a full free audit, which brings your security and SEO checks together in one PDF report.
Frequently asked questions
Is this SSL certificate checker free?
Yes, free with no signup, up to 15 checks per hour.
How long do SSL certificates last?
Free automated certificates (such as Let's Encrypt) last 90 days; paid certificates are capped at about 13 months. Either way automated renewal matters: manual renewal is easy to forget.
What happens when a certificate expires?
Browsers show a full-page "not private" warning, and most visitors leave rather than proceed, so it acts like downtime for conversions.
How do I stop my certificate expiring?
Use a host or CDN with automated renewal, or a tool such as Certbot on your own server to renew and reload automatically.
Does this check mixed content too?
No. For HTTPS and mixed-content checks use the HTTPS checker; this tool focuses on the certificate itself.