Verify any website's SSL/TLS certificate in seconds. Our free SSL checker shows the issuer, validity dates, subject and SAN domains, key strength, chain of trust, and supported TLS versions — useful for confirming an HTTPS rollout, debugging certificate errors, and spotting weak crypto.
Our SSL Checker performs global probes, with a strong emphasis on data centers and certificate authorities within the United States, providing comprehensive worldwide coverage.
The tool performs a real TLS handshake with the server on port 443, exactly as a browser would, and then reports what came back instead of rendering a page. During the handshake the server presents its certificate chain: the leaf certificate for the site, one or more intermediates, and a pointer up to a root that browsers already trust.
Valid from and valid to define the window in which browsers accept the certificate; anything under two weeks remaining deserves attention today. Issuer names the certificate authority — Let's Encrypt and Google Trust Services for free automated certificates, DigiCert or Sectigo for paid and extended-validation ones. Browsers make no visible distinction, so a free certificate is not a weaker one.
| Version | Status | Recommendation |
|---|---|---|
| TLS 1.3 | Modern, fastest | Required for new deployments |
| TLS 1.2 | Widely supported | Keep enabled as a fallback |
| TLS 1.1 | Deprecated | Disable — blocked by major browsers |
| TLS 1.0 | Insecure | Disable — known POODLE/BEAST issues |
| SSL 3.0 | Broken | Must be disabled |
Before launching a new website, developers and site owners can use the SSL Checker to perform a final security audit, ensuring the SSL/TLS certificate is correctly installed, valid, and trusted by all major browsers. This prevents Day 1 security warnings and builds immediate user trust.
After migrating a website to a new host or server, an SSL Checker quickly verifies that the SSL certificate has been properly transferred and configured. It ensures a seamless transition without any downtime or security interruptions related to HTTPS.
Webmasters and SEOs can schedule regular certificate expiry checks to proactively monitor their SSL/TLS certificates. This prevents unexpected expirations that lead to security warnings, downtime, and negative impacts on search engine rankings and user access.
For pages experiencing 'mixed content' warnings where secure HTTPS pages load insecure HTTP resources, the SSL Checker can identify the presence of such issues. It helps pinpoint the insecure elements that need to be updated to HTTPS.
Yes — free, unlimited, no signup.
An SSL Checker is a free online tool that inspects your website's SSL/TLS certificate. You need one to verify that your certificate is correctly installed, valid, not expired, and trusted. It ensures your website uses HTTPS for secure communication, preventing security warnings and building user trust. Regular checks are vital for maintaining website security and SEO.
Mixed content occurs when an HTTPS page attempts to load resources (like images, scripts, or CSS) over an unencrypted HTTP connection. This compromises security and triggers browser warnings. Our SSL Checker helps identify these insecure resources, allowing you to update them to HTTPS.
Yes, a core function of our SSL Checker is to perform a robust certificate expiry check. It clearly displays the certificate's 'Valid From' and 'Valid To' dates, immediately highlighting if your certificate has expired or is nearing its expiration. This helps prevent unexpected outages.
Enter your domain above. We connect over HTTPS and report issuer, expiry, chain, and TLS version.
Default is 443. Many services (SMTPS 465, IMAPS 993, custom) also serve TLS — supply a port if needed.
Usually a missing intermediate. Re-install the full chain bundle from your CA — Let's Encrypt's fullchain.pem is the canonical example.
Let's Encrypt expires every 90 days and most clients renew automatically at day 60. Commercial certs typically run 1 year.
Run this free SSL checker before launches and after every certificate renewal to confirm HTTPS is valid, complete and trusted worldwide. Check expiry early, verify the chain, then use the HTTP header checker to confirm HSTS and redirect behaviour are configured correctly.