SSL certificate and HTTPS checker
Check a domain's HTTPS setup: whether its certificate is accepted when we connect, whether http:// redirects to https://, whether the www name works too, its HSTS header and its CAA records. We say plainly what this check can't show, such as the expiry date.
How to use the SSL Certificate Checker
- 1Enter your domain, such as yoursite.com.
- 2Read the verdict: HTTPS works, or the connection failed the certificate check.
- 3Fix anything flagged: a missing http-to-https redirect, the www name, HSTS or CAA.
- 4Click the padlock in your browser to see the certificate's issuer and expiry date.
Frequently asked questions
Why doesn't this checker show the certificate expiry date?
It runs on Cloudflare Workers, which accept or reject a certificate but don't expose its details, and we don't use paid or restricted certificate APIs. Your browser's padlock or a Certificate Transparency search shows the dates.
What is a CAA record?
A DNS record listing which certificate authorities may issue certificates for your domain, such as letsencrypt.org. It's optional, and it stops other authorities from issuing one by mistake or for an attacker.
What is HSTS and should I enable it?
Strict-Transport-Security tells browsers to always use HTTPS for your site, even if someone types http://. Enable it once your whole site, including subdomains you list, works over HTTPS.
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