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SSL Certificate Checker

Is your SSL valid - days left before visitors see a security warning.

Enter a domain - e.g. yourdomain.com or sub.yourdomain.com

Valid or expired

Is the certificate active right now?

Expiry countdown

Exact date and days remaining until renewal

Chain trust

Will Chrome, Firefox, Safari, Brave, and other browsers trust the full chain?

No account required · Free · Results in under 1s

What is an SSL certificate checker?

TLS validation and expiry in plain terms

An expired SSL certificate triggers a full-screen warning in Chrome, Firefox, Safari, Brave, and other major browsers - most visitors leave without completing a purchase or sign-up. Our checker validates certificates against the same trust rules those browsers use.

A broken SSL chain or hostname mismatch triggers the same warnings even when a certificate looks valid on paper. A free SSL certificate checker lets you verify certificate trust and check SSL expiry before visitors see security warnings.

Run a one-time free SSL check after server changes or before renewals. Add the domain to TotalSiteControl monitoring for automated expiry alerts 30, 14, and 7 days before lapse.

Stop guessing renewal dates — monitor certificates automatically

Free TotalSiteControl monitoring - email alerts, no credit card required.

Expiry alerts

Get notified 30, 14, and 7 days before your certificate expires.

Chain validation

Scheduled checks catch broken intermediate certificates before browsers do.

Check history

See past results and trends - useful for audits and SLA reporting.

Instant results · No signup · Check anytime

Frequently asked questions

What does an SSL certificate checker do?

It connects to a domain's HTTPS server, retrieves the TLS certificate, and reports whether it is valid, who issued it, when it expires, and if the certificate chain is trusted.

Is this SSL certificate checker free?

Yes. Enter any public domain and get instant results - no signup, no credit card, and no limit on one-off checks. Optional monitoring alerts are also free to start.

Why does Chrome show "Your connection is not private"?

Browsers show this when HTTPS cannot be trusted - usually because the certificate expired, the chain is incomplete, or the certificate name does not match the hostname. Run a free SSL check on the exact URL visitors use (including www) to see which issue applies.

What happens when an SSL certificate expires?

Browsers display security warnings and may block access entirely. Visitors lose trust, SEO can suffer, and API clients may fail until the certificate is renewed.

What is an SSL certificate chain?

A certificate chain links your site certificate to a trusted root CA through one or more intermediate certificates. If intermediates are missing on the server, browsers may reject an otherwise valid certificate. Our checker validates the full chain, not just the expiry date.

How do I fix SSL certificate errors?

It depends on the result: renew or reinstall if expired; upload missing intermediate certificates if the chain fails; install a certificate that includes the correct hostname if there is a name mismatch. After fixing, run the check again from the same hostname your users visit.

Can I check a subdomain?

Yes - enter any hostname such as www.yourdomain.com or api.yourdomain.com. We connect to its HTTPS endpoint and inspect the certificate served for that name.

How often should I check my SSL certificate?

Check manually before renewals or after server changes. For production sites, automated monitoring with expiry alerts is recommended so you are notified before certificates lapse.

Never miss an SSL certificate expiry again

Free monitoring with alerts 30, 14, and 7 days before your certificate expires.

Start Monitoring - free