TLS Cipher Strength Checker
Check TLS cipher suite strength and security configurations.
Last reviewed by the Radiatus Cloud team
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Not all TLS ciphers are equal
A TLS connection can be encrypted and still weak, because the cipher suite it negotiated determines the real strength. This tool reads a cipher suite name and rates its security: the key exchange, the bulk cipher and the mode, and whether any part of it is outdated. A suite is only as strong as its weakest component.
What separates a strong suite from a weak one
Strong suites use forward-secret key exchange, so recording the traffic today and stealing the key tomorrow does not decrypt the past. They use a modern authenticated cipher like AES-GCM or ChaCha20-Poly1305, which encrypt and verify integrity together. Weak suites cling to RC4, plain CBC without proper authentication, small keys, or non-forward-secret RSA key exchange. The name encodes all of this once you know how to read it, which is what the checker does for you.
A quick sanity check for a configuration
Whether you are choosing which suites a server should offer or reading a scan of one, rating each suite tells you what to keep and what to drop. The safe modern set is small; everything else is compatibility baggage that should be retired as clients allow. The analysis runs in your browser.
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- DNS Misconfiguration — Analyze DNS records (TXT, SPF) for security gaps.
- TLS Compat Tester — Check client-server compatibility for TLS versions.
- Firewall Rule Risk — Evaluate firewall rules for over-permissive exposure.
Frequently Asked Questions
What makes a TLS cipher suite strong?
Forward-secret key exchange, a modern authenticated cipher such as AES-GCM or ChaCha20-Poly1305, and an adequate key size. A suite is only as strong as its weakest part.
What is forward secrecy and why does it matter?
It means each session uses an ephemeral key, so recording encrypted traffic now and stealing the server key later does not decrypt the past sessions. Non-forward-secret RSA key exchange lacks this.
Which ciphers are considered weak?
RC4, plain CBC modes without proper authentication, small keys, and export-grade ciphers. They should be retired in favour of authenticated modes.
How do I read a cipher suite name?
It names the key exchange, authentication, bulk cipher and mode in sequence. The checker interprets each part and rates the whole.
Is my input uploaded?
No. The analysis runs entirely in your browser.
Privacy & Security
Checking done locally.
About This Tool
This tool runs entirely in your browser. No data is sent to any server, ensuring complete privacy. Simply use the interface above to get started — no registration or login required.
Disclaimer: This tool is provided "as is" without warranty of any kind. Results are for educational and utility purposes.
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Port Scanner
NetworkCheck which common ports respond on a host and understand what each exposed service means. Scan only systems you are authorised to test.
DNS Misconfiguration
NetworkAnalyze DNS records (TXT, SPF) for security gaps.
TLS Compat Tester
NetworkCheck client-server compatibility for TLS versions.