SSL Certificate Checker
Check SSL certificate details and expiration
Calculator
About This Tool
This SSL checker provides educational information about SSL certificates. Due to browser security restrictions, client-side JavaScript cannot directly inspect SSL certificates of external websites. The results shown are simulated for demonstration purposes.
Verify with External SSL Checkers
For accurate, real-time SSL certificate verification, use these trusted tools:
SSL Certificate Best Practices
Use TLS 1.2 or higher
Disable SSL 2.0, 3.0, and TLS 1.0/1.1
Renew before expiration
Set reminders 30 days in advance
Use strong key sizes
RSA 2048+ bits or ECC 256+ bits
Enable HSTS
Force HTTPS connections
Include all domains
Use SAN for www and subdomains
Monitor certificate transparency
Detect unauthorized certificates
Common SSL Certificate Errors
NET::ERR_CERT_DATE_INVALID
Certificate has expired or is not yet valid
NET::ERR_CERT_COMMON_NAME_INVALID
Domain name doesn't match the certificate
NET::ERR_CERT_AUTHORITY_INVALID
Certificate is self-signed or from untrusted CA
SSL_ERROR_WEAK_SERVER_CERT_KEY
Certificate uses weak encryption (e.g., 1024-bit RSA)
How to Use
Learn how to check SSL certificate status and security details for any website
Enter the domain
Type or paste the domain name you want to check (e.g., example.com or https://example.com)
Click Check SSL
Press the Check SSL button to retrieve certificate information
Review certificate details
Examine the certificate status, issuer, expiration date, and security protocols
Note any warnings
Pay attention to warnings about expiring certificates (less than 30 days) or security issues
Frequently Asked Questions
An SSL (Secure Sockets Layer) certificate is a digital certificate that authenticates a website's identity and enables an encrypted connection. It protects sensitive data like passwords, credit card numbers, and personal information during transmission between a web server and browser.
Look for HTTPS in the URL instead of HTTP, and a padlock icon in the browser's address bar. Clicking the padlock shows certificate details. Valid certificates show the issuer, expiration date, and domain name. Browsers will warn you if a certificate is expired, self-signed, or has other issues.
SSL certificates are crucial for security, trust, and SEO. They encrypt data to prevent hackers from intercepting sensitive information, display trust indicators (padlock) that increase visitor confidence, and Google uses HTTPS as a ranking factor, so sites with SSL may rank higher in search results.
When an SSL certificate expires, browsers display security warnings to visitors, which can significantly reduce traffic and trust. Your site may become inaccessible to some users, e-commerce transactions may fail, and your SEO rankings could be negatively impacted. It's important to renew certificates before expiration.
TLS (Transport Layer Security) is the successor to SSL and is more secure. While people still say "SSL," most modern websites actually use TLS 1.2 or TLS 1.3. TLS provides stronger encryption algorithms and better security features. SSL 2.0 and 3.0 are considered insecure and deprecated.
There are three main types: Domain Validated (DV) certificates verify domain ownership only, Organization Validated (OV) certificates verify the organization's identity, and Extended Validation (EV) certificates provide the highest level of trust with extensive verification. There are also single-domain, multi-domain (SAN), and wildcard certificates.
Network & Security
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