SSL Rating Calculator
Calculate an SSL/TLS security rating based on your server's TLS configuration. Select protocol version, key exchange, certificate strength, cipher suites, HSTS status, forward secrecy, and certificate validation to get a letter grade from A+ to F. Use what-if analysis to see how different configurations affect your rating, with specific recommendations for improvement.
Select your server's TLS configuration to calculate an SSL rating. Adjust each setting to see how different configurations affect your security grade.
Modern - best security and performance
Best - provides forward secrecy
Standard - 2048-bit RSA (minimum recommended)
Best - authenticated encryption
Good - HSTS with long max-age
Best - full forward secrecy
Patched against CVE-2014-0160
Certificate from trusted CA, in date
Very Good
92/100 - Very good - strong security with minor room for improvement
Findings
- ✅ TLS 1.3 with ECDHE, AEAD ciphers, and forward secrecy - modern configuration bonus
Why Use Our SSL Rating Calculator?
Industry-Standard Grading
Our rating algorithm follows SSL Labs criteria - the same methodology used by security professionals worldwide. Scores are calculated from 8 weighted factors including protocol version, key exchange, cipher strength, and certificate validation to produce a letter grade from A+ to F.
What-If Analysis
Adjust any setting and instantly see how it affects your rating. Experiment with different protocol versions, cipher suites, and security headers to understand which configuration changes will have the biggest impact on your overall security grade.
Actionable Recommendations
Each rating comes with specific, actionable recommendations for improvement. Learn exactly which protocols to upgrade, which ciphers to disable, and which security headers to enable to achieve a higher SSL rating.
Educational Reference Tool
Perfect for students learning about TLS security, system administrators evaluating configurations, and developers understanding the impact of different TLS settings. Each option includes a clear description of its security implications.
Common Use Cases for SSL Rating
Server Configuration Review
System administrators can evaluate their current TLS configuration by matching their server settings to the calculator inputs. Identify weak protocols, outdated ciphers, and missing security headers that could lower the overall security rating.
Cybersecurity Education
Students learning about TLS/SSL security can experiment with different configurations to understand how each factor affects the overall rating. Visual feedback shows the real-world impact of protocol choices, making abstract security concepts tangible.
Development & Staging Testing
Developers can test different TLS configurations during development to ensure their applications meet security best practices before deployment. Verify that development certificates and settings would receive an acceptable rating.
Compliance & Audit Preparation
Prepare for security audits (PCI DSS, HIPAA, FedRAMP) by identifying TLS configuration gaps. Use the rating calculator to understand which changes are needed to meet compliance requirements for secure communication.
Security Upgrade Planning
Plan TLS security upgrades by comparing current vs target configurations. See exactly which protocol upgrades, cipher changes, and header additions are needed to move from a C or B rating to an A+ rating.
Security Assessment Reports
Generate detailed findings and recommendations for security assessment reports. The tool provides clear explanations of each security issue found and actionable steps to fix them, ready for inclusion in technical reports.
Understanding SSL/TLS Security Ratings
What is an SSL Rating?
An SSL rating (also called a TLS security rating) is a letter grade (A+ through F) that represents the overall security posture of a TLS server configuration. Inspired by the widely respected Qualys SSL Labs server test, the rating evaluates multiple factors including the protocol version, key exchange mechanism, certificate strength, cipher suite choices, HSTS support, and forward secrecy capabilities. Each factor is weighted by its security importance to produce a combined score out of 100.
Key Factors in the Rating
- Protocol Version (25%) - The highest TLS protocol version supported by the server. TLS 1.3 is the most secure and receives full marks. SSL 2.0 and 3.0 are considered broken and receive near-zero scores.
- Certificate Strength (20%)- The cryptographic strength of the server's certificate key. ECDSA P-256 and above are strong choices. RSA keys should be at least 2048 bits. RSA 1024 and DSA 1024 are below current recommendations.
- Key Exchange (15%) - How the session key is established. ECDHE (Elliptic Curve Diffie-Hellman Ephemeral) is the best option as it provides forward secrecy. Static key exchanges that lack forward secrecy receive lower scores.
- Cipher Suite (15%) - The encryption algorithm used for the actual data transfer. AEAD ciphers (AES-GCM, CHACHA20-POLY1305) are the gold standard. CBC mode ciphers are adequate but carry theoretical risks. RC4, DES, and export-grade ciphers are considered broken.
- Other Factors (25%) - HSTS enforcement, forward secrecy coverage, vulnerability status (Heartbleed), and certificate validation status each contribute to the overall rating.
How to Achieve an A+ Rating
Achieving the highest A+ rating requires meeting all of these criteria: supportingTLS 1.3 (with TLS 1.2 as a minimum fallback), using ECDHE key exchange for forward secrecy, deploying a valid certificate from a trusted CA with RSA 2048+ or ECDSA P-256+ strength, prioritizing AEAD ciphers (AES-GCM, CHACHA20-POLY1305), enabling HSTS with a max-age of at least 6 months (ideally preloaded), ensuring all cipher suites provide forward secrecy, and beingnot vulnerable to Heartbleed. An A+ rating signals that the server follows all current security best practices.
Common SSL/TLS Misconfigurations
The most common issues that lower SSL ratings include: supporting outdated protocols (SSL 3.0, TLS 1.0), using static RSA or DH key exchanges (no forward secrecy), weak certificate keys (RSA 1024), enabling broken ciphers (RC4, DES, export-grade), missing or weak HSTS policies, and expired or self-signed certificates. Many of these issues can be fixed by updating server configuration files - our tool provides specific recommendations for each issue found.
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Frequently Asked Questions About SSL Ratings
An SSL rating is a letter grade (A+ to F) that indicates how secure a TLS server configuration is. It matters because a low rating means your server has security weaknesses that could be exploited by attackers. Many compliance frameworks (PCI DSS, HIPAA) require strong TLS configurations, and browsers may warn users about connections to servers with poor security.
Our rating is calculated from 8 weighted factors: protocol version (25%), certificate strength (20%), key exchange (15%), cipher suite (15%), HSTS status (10%), forward secrecy (5%), Heartbleed vulnerability (5%), and certificate validation (5%). Each factor is scored individually and combined into a total score out of 100, which maps to a letter grade. Critical security issues like Heartbleed or revoked certificates can force a maximum grade cap regardless of other factors.
TLS 1.3 (released in 2018) is significantly more secure and faster than TLS 1.2 (2008). TLS 1.3 removes obsolete and insecure features, reduces the handshake from 2 round trips to 1, mandates forward secrecy for all cipher suites, and removes support for weak algorithms. TLS 1.2 is still considered strong when properly configured, but TLS 1.3 is the recommended modern standard.
Forward secrecy ensures that if a server's private key is compromised in the future, past encrypted sessions cannot be decrypted. This is achieved through ephemeral key exchanges (ECDHE or DHE) where a unique session key is generated for each connection and then discarded. Without forward secrecy, an attacker who obtains the private key can decrypt all recorded past traffic - making it one of the most important security features for protecting historical communications.
HSTS (HTTP Strict Transport Security) tells browsers to always connect to your server over HTTPS, preventing downgrade attacks and SSL stripping. Enabling HSTS with a long max-age (at least 6 months or 31536000 seconds) improves your rating. Adding your domain to browser HSTS preload lists provides the strongest protection and contributes to the highest possible score.
Heartbleed (CVE-2014-0160) is a critical vulnerability in OpenSSL 1.0.1 through 1.0.1f that allows attackers to read sensitive memory from servers, including private keys and user data. While patched versions have been available since 2014, some legacy servers may still be vulnerable. Any server affected by Heartbleed receives a maximum rating of E, and fixing this is the highest priority security action.
For RSA keys, the minimum recommended size is 2048 bits. RSA 4096 provides additional security margin but requires more computation. For ECDSA keys, P-256 (secp256r1) is the recommended minimum - it provides equivalent security to RSA 3072 with less computational overhead. ECDSA P-384 and P-521 offer even stronger security. Avoid RSA 1024 and DSA 1024 as they are below current security recommendations.
Yes, this SSL rating calculator is completely free with no signup, no account, and no usage limits. All calculations are performed locally in your browser - no data is sent to any server. Use it as many times as you need to evaluate different TLS configurations.