Advanced SSL Checker

Instantly verify SSL/TLS certificate details. Check validity, expiry dates, issuer validation, and security chain for any domain.

SSL Certificate Check

Enter a domain name to analyze its SSL/TLS configuration

We support HTTPS domains. This tool is totally free.

What is an SSL Certificate?

SSL (Secure Sockets Layer) is the standard technology for keeping an internet connection secure and safeguarding any sensitive data that is being sent between two systems. An SSL certificate is a digital certificate that authenticates a website's identity and enables an encrypted connection.

When a website has an SSL certificate, its URL starts with HTTPS (Hypertext Transfer Protocol Secure) containing the letter "S" for Secure, and a padlock icon appears in the browser's address bar.

Why Check Your SSL Certificate?

  • Avoid Expiry Downtime: SSL certificates have expiration dates. If they expire, browsers will show a "Not Secure" warning to your visitors, drastically hurting your traffic and trust.
  • Verify Installation: Ensure that your certificate is correctly installed and that the chain of trust (the path from your certificate to a trusted root CA) is valid.
  • Security Compliance: Check for weak cipher suites or outdated protocols that could leave your users vulnerable to attacks.
  • SEO Benefits: Google uses HTTPS as a ranking signal. Ensuring a valid SSL certificate helps maintain your search engine rankings.

How to Use the Advanced SSL Checker

1

Enter Domain

Type the domain name (e.g., example.com) you want to test in the input field. You can also paste the full URL.

2

Analyze

Click the "Check SSL" button to initiate the scan. Our tool will connect to the server and retrieve certificate details.

3

Review Report

Get a clear report showing validity status, expiration date, issuer, and other technical details to ensure your site is secure.

Frequently Asked Questions

What should I do if I get a NET::ERR_CERT_AUTHORITY_INVALID error?

This error often indicates that the browser doesn't trust the certificate's issuer. It's frequently caused by using a self-signed SSL certificate, having missing intermediate certificates, or the root CA not being in the browser's trust store. To fix this, ensure you install the full certificate chain on your web server. Check your site with our free online SSL certificate checker to identify chain issues.

Why is my website showing a "Not Secure" warning despite having SSL?

This is often due to Mixed Content errors, where an HTTPS page loads resources (images, scripts) over insecure HTTP. It can also happen if the certificate has expired or the Common Name (CN) doesn't match the URL. Use the browser console to check for mixed content or our tool to verify the Subject Alternative Names (SANs) and SSL expiration date.

How do I fix the "SSL Certificate Not Trusted" error?

This error usually points to an incomplete certificate chain. When you install an SSL, you often need to install "Intermediate Certificates" that link your site's certificate to a trusted Root CA. If these are missing, mobile devices and some browsers may reject the connection. Our tool checks for missing intermediate certificates automatically.

What causes an ERR_SSL_PROTOCOL_ERROR?

This generic error can result from server misconfiguration, such as enabling only outdated protocols (SSLv3, TLS 1.0) or incompatible Cipher Suites. It can also occur if the system date is incorrect or a firewall is interfering. Ensure your server supports modern TLS protocol versions (TLS 1.2 or 1.3) and secure ciphers.

What is an SSL Handshake Failure?

An SSL Handshake Failed error occurs when the client and server cannot agree on security parameters. Common causes include Protocol Mismatch (e.g., client wants TLS 1.3, server only has TLS 1.0), Cipher Suite Mismatch, or Server Name Indication (SNI) issues. Diagnosing this often requires checking the server's supported protocols.

How does a "Common Name Mismatch" error happen?

This occurs when the certificate's domain name doesn't match the address in the browser bar. For example, the certificate is for example.com but you visited www.example.com. To prevent this, ensure your certificate covers all variations, often handled by Wildcard SSL certificates or adding domains to the SANs (Subject Alternative Names) list.

How can I check for SSL expiry to avoid downtime?

You can use command-line tools like OpenSSL or our SSL certificate expiration date checker. Monitoring expiry is crucial because an expired certificate immediately triggers browser warnings, blocking traffic. We recommend renewing at least 30 days before the Valid Until date.

What is the difference between DV, OV, and EV SSL certificates?

DV (Domain Validation) only verifies domain ownership and is issued quickly. OV (Organization Validation) verifies the business entity. EV (Extended Validation) requires strict background checks. While all provide the same encryption level, OV and EV offer higher trust for users.

This Tool is Totally Free!

Perform unlimited SSL checks for free. Ensure your websites are always secure without paying for premium monitoring services.

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