SERPInsight

SSL/TLS Grade Checker

Verify your website's encryption standards. Our scanner analyzes your certificate chain, key strength, and validity to generate a comprehensive security grade.

Analyzes Certificate Validity, Key Strength (RSA/ECDSA), and Trust Chain.

The SERPInsight SSL/TLS Grade Checker

SSL (Secure Sockets Layer) and its successor TLS (Transport Layer Security) are the standard technologies for keeping an internet connection secure. They safeguard sensitive data being sent between two systems, preventing criminals from reading and modifying any information transferred, including potential personal details.

A valid certificate is now a requirement for modern SEO. Search engines like Google label non-HTTPS sites as "Not Secure," which can drastically increase bounce rates. Our tool performs a deep handshake analysis to ensure your certificate is valid, trusted, and using modern cryptographic standards.

How our tool works

  • 1

    Handshake Emulation

    We initiate a secure connection to your server (port 443) just like a web browser does, capturing the certificate chain.

  • 2

    Deep Inspection

    We parse the X.509 certificate data to extract details about the issuer, validity period, and cryptographic key strength (RSA/ECDSA).

  • 3

    Trust Scoring

    We verify that the certificate is not self-signed, has not expired, and uses strong keys (2048-bit+) to assign a letter grade.

Understanding SSL Metrics

Validity Period

Ensures the certificate is currently active and not expired. Modern best practices suggest renewing certificates every 60-90 days.

Key Strength

The size of the cryptographic key used to encrypt data. 2048-bit is the modern standard for RSA keys; anything less is considered insecure.

Chain of Trust

Verifies that the certificate was issued by a trusted Certificate Authority (CA) like Let's Encrypt or DigiCert, and not "Self-Signed".

Signature Algo

The mathematical function used to sign the certificate. SHA-256 is the standard. Older algorithms like SHA-1 are vulnerable and rejected.

Common Name (CN)

The primary domain name associated with the certificate. This must match the URL in the browser address bar exactly to avoid warnings.

SNI Support

Server Name Indication allows multiple secure websites to be served from the same IP address. It is required for modern hosting environments.

How We Calculate Your Grade

Our algorithm assigns points based on the strength and validity of your encryption.

Grading Tiers
A
Score 90 - 100
Perfect. Valid certificate, >60 days remaining, strong key (2048+ bits).
B
Score 75 - 89
Good. Valid certificate, but expires in less than 30-60 days.
C
Score 50 - 74
Warning. Valid, but expires in less than 30 days. Renew immediately.
D
Score 30 - 49
Weak. Expires in < 7 days or uses weak encryption keys (< 2048 bits).
F
Score 0 - 29
Critical. Expired, Self-Signed, or Hostname Mismatch.

Scoring Weights

  • Validity > 60 Days +20 pts
  • Key Size ≥ 2048 bit +40 pts
  • Trusted Issuer (CA) +40 pts
  • Weak Key (< 2048 bit) -50 pts
  • Expired / Self-Signed Auto F

Pro Tip: To maintain an A Grade, ensure your certificate is automatically renewed (e.g., via Certbot) at least 30 days before expiration.

Frequently Asked Questions

What is an SSL Certificate?
SSL (Secure Sockets Layer) creates an encrypted link between a web server and a web browser. It ensures that all data passed between the two remains private and integral.
Why did I get an F grade?
An 'F' grade typically means the certificate is either Expired, Self-Signed (not trusted by browsers), or the domain name on the certificate doesn't match the website URL you are testing.
Does SSL affect SEO rankings?
Yes. Google uses HTTPS as a ranking signal. Websites without a valid SSL certificate may be penalized in search rankings, and Chrome will display a visible "Not Secure" warning to your visitors.

Why use our SSL Checker?

Fast, accurate, and free security diagnostics.

Instant Analysis

Get real-time feedback on your server's security handshake without installing any software or command-line tools.

Multi-Server Support

We resolve and list all IP addresses associated with your domain to check consistency across Load Balancers and CDNs.

Deep Inspection

We analyze hidden details like signature algorithms (SHA-256) and key bits (2048 vs 4096) to ensure modern compliance.

Free & Private

No sign-up required. Your searches are processed securely and we do not store your data or search history.

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