SSL Certificate Checker
Verify SSL/TLS certificate validity, expiration, issuer, and security grade for any domain.
Check if a website's SSL certificate is properly configured, valid, and secure. Our tool analyzes certificate details including issuer information, validity period, encryption standards, and provides an overall security grade.
Certificate Details
Domain
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Issuer
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Valid From
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Valid To
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Days Until Expiry
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Protocol
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Key Size
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Signature
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Error
An error occurred while checking the SSL certificate.
What is SSL/TLS?
SSL (Secure Sockets Layer) and TLS (Transport Layer Security) are cryptographic protocols designed to provide secure communication over a computer network. They are widely used on the Internet to protect the privacy and integrity of data exchanged between web browsers and servers.
Why SSL/TLS is Important
- Data Encryption: Encrypts data transmitted between the browser and server, preventing eavesdropping.
- Data Integrity: Ensures that data is not tampered with during transmission.
- Authentication: Verifies the identity of the website, ensuring users are communicating with the legitimate server.
- Trust: Browsers display a padlock icon and HTTPS to indicate secure connections.
- SEO Benefits: Search engines like Google prioritize HTTPS websites in search results.
Understanding SSL Grades
SSL grades range from A+ to F, with A+ being the most secure and F being the least secure. The grade is based on various factors including:
- Certificate Validity: Is the certificate current and not expired?
- Protocol Version: Is the site using modern TLS protocols (TLS 1.2 or 1.3)?
- Encryption Strength: Are strong encryption algorithms being used?
- Certificate Chain: Is the certificate chain properly configured?
- Vulnerabilities: Are there known SSL/TLS vulnerabilities?
Common SSL Issues
- Expired Certificate: The certificate has passed its validity period.
- Self-Signed Certificate: The certificate is not issued by a trusted Certificate Authority (CA).
- Mismatched Domain: The certificate does not match the domain name.
- Weak Encryption: Using outdated or weak encryption algorithms.
- Missing Intermediate Certificates: Incomplete certificate chain.
How to Fix SSL Issues
- Renew Expired Certificates: Contact your CA to renew expired certificates.
- Use Trusted CA: Obtain certificates from reputable Certificate Authorities like Let's Encrypt, DigiCert, or Comodo.
- Update Server Configuration: Enable modern TLS protocols and strong ciphers.
- Complete Certificate Chain: Ensure all intermediate certificates are properly installed.
- Use Certificate Management Tools: Automate certificate renewal with tools like Certbot or commercial solutions.