SSL Certificate Checker
Verify SSL/TLS certificates, check expiry dates, and validate your HTTPS setup.
What is an SSL Certificate?
An SSL (Secure Sockets Layer) certificate is a digital certificate that authenticates a website's identity and enables an encrypted connection between a web server and a browser. SSL certificates use the TLS (Transport Layer Security) protocol to secure data transmitted over the internet, protecting sensitive information like login credentials, credit card numbers, and personal data from interception by malicious actors.
SSL certificates contain the domain name, the certificate authority (CA) that issued it, the CA's digital signature, the associated subdomains, the issue and expiry dates, and the public key. When a browser connects to an SSL-secured website, the server presents its certificate for verification before establishing an encrypted session.
Why SSL Matters for Your Website
SSL certificates are essential for any modern website. Here's why:
- Data Encryption — Protects sensitive information transmitted between visitors and your server from eavesdropping and man-in-the-middle attacks.
- SEO Ranking — Google uses HTTPS as a ranking signal. Sites with valid SSL certificates tend to rank higher in search results.
- User Trust — The padlock icon in the browser address bar signals to visitors that your website is legitimate and their data is safe.
- Compliance — Many regulations (PCI DSS, GDPR, HIPAA) require encrypted data transmission, making SSL certificates mandatory.
- Browser Warnings — Modern browsers display prominent "Not Secure" warnings for sites without SSL, driving visitors away.
How to Fix SSL Certificate Errors
Common SSL errors and how to resolve them:
🔴 Certificate Expired
Renew your SSL certificate through your certificate authority or hosting provider. Consider using Let's Encrypt for free, auto-renewing certificates managed by tools like Certbot.
🔴 Certificate Name Mismatch
The domain in the certificate doesn't match the URL. Reissue the certificate with the correct domain name, or use a wildcard certificate (*.example.com) to cover all subdomains.
🔴 Untrusted Certificate Authority
Self-signed certificates trigger browser warnings. Use a certificate from a trusted CA such as Let's Encrypt, DigiCert, Sectigo, or Comodo.
🔴 Incomplete Certificate Chain
Install the intermediate certificates provided by your CA. Most CAs provide a "full chain" or "CA bundle" file that should be configured on your server alongside your primary certificate.
🔴 Mixed Content Warnings
Ensure all resources (images, scripts, stylesheets) are loaded over HTTPS. Update hardcoded HTTP URLs in your code, or use protocol-relative URLs and Content Security Policy headers.