SSL Certificate Checker
This SSL Certificate Checker validates a domain’s HTTPS certificate, displays issuer details, validity dates, expiration status, signature algorithm, and assigns an overall security grade.
About This Tool
The SSL Certificate Checker helps you verify a domain’s HTTPS certificate configuration and identify potential security issues. By connecting directly to the server, this tool retrieves real-time certificate details including issuer, validity period, signature algorithm, and expiration status.
SSL certificates encrypt data between users and websites. If a certificate is expired, misconfigured, or using weak cryptographic standards, it can expose visitors to security risks and browser warnings. Monitoring SSL health is essential for maintaining secure encrypted connections.
This tool allows you to:
- View certificate issuer information
- Check certificate validity start and expiration dates
- Calculate days remaining before expiry
- Identify signature algorithm strength
- Evaluate overall SSL security grade
The SSL check is performed in real time using native server-side validation. No domain data is stored, logged, or shared.
Frequently Asked Questions
What does the SSL Certificate Checker do?
The SSL Certificate Checker verifies a website’s HTTPS certificate and displays important details such as issuer, validity period, signature algorithm, key type (RSA or ECC), and remaining days before expiration.
How does this SSL checker work?
This tool connects directly to the domain using a secure socket connection and retrieves the SSL certificate from port 443. It then parses certificate data using native PHP OpenSSL functions.
No external APIs are used.
What does the Security Grade mean?
The grade (A–F) is calculated based on:
1.Certificate validity status
2.Remaining validity days
3.Key type (RSA or ECC)
4.Key length
5.Signature algorithm
6.Whether the certificate is self-signed
Higher grades indicate stronger encryption and proper configuration.
What is a wildcard certificate?
A wildcard certificate secures a main domain and all its subdomains (e.g., *.example.com). The tool detects whether the certificate uses a wildcard.
Does this tool store any SSL data?
No. The SSL certificate is analyzed in real time and no domain data is stored, logged, or shared.
