CRYPTOGRAPHIC TRANSPORT AUDIT

TLS Version Checker – Test TLS 1.0, 1.1, 1.2 & 1.3 Protocols

Audit supported Transport Layer Security (TLS) protocol versions across TLS 1.0, TLS 1.1, TLS 1.2, and TLS 1.3. Detect deprecated legacy ciphers (POODLE, BEAST, DROWN) and verify forward-secret cipher suites.

RFC 8446 TLS 1.3 Aligned

NIST SP 800-52 Rev. 2 Verification

Live Cryptographic Handshake Probe

Zero Account Required

ℹ️ Scope & Limitation Notice: Queries public HTTPS endpoints on port 443; internal firewalled ports or proprietary non-standard ports cannot be reached.

Launch Tool How It Works & Guide

TLS Handshake Protocol Spectrum

RFC 8446 Cryptography

1 TLS 1.0 & 1.1 Probe

Deprecated: BEAST, POODLE & SHA-1

2 TLS 1.2 Handshake

AEAD ciphers & PFS key exchange

3 TLS 1.3 Handshake

1-RTT handshake, 0-RTT resumption

4 Forward Secrecy Verification

ECDHE ephemeral key exchange

Mode: Live TLS Handshake Probe Sample Preview

Check a Website's TLS Versions

Port 443 Handshake Engine

Enter a public domain or HTTPS website to test which supported TLS protocol versions the server accepts on port 443.

FUNCTIONAL ARCHITECTURE

What Does the TLS Version Checker Do?

The TLS Version Checker initiates live cryptographic handshakes with any domain or server to determine which Transport Layer Security (TLS) and Secure Sockets Layer (SSL) protocols are supported.

It flags deprecated and insecure protocols (SSL 2.0, SSL 3.0, TLS 1.0, and TLS 1.1) that violate modern compliance standards (PCI DSS v4.0, HIPAA, and NIST SP 800-52), while confirming support for modern, secure TLS 1.2 and TLS 1.3.

STEP-BY-STEP METHODOLOGY

How the TLS Version Checker Works

Initiate ClientHello Probes

Transmits individual TLS ClientHello handshake messages targeting TLS 1.0, 1.1, 1.2, and 1.3.

Evaluate ServerHello Responses

Analyzes server cryptographic handshake responses to confirm supported protocol versions and cipher suites.

Audit Cryptographic Security

Checks for Perfect Forward Secrecy (PFS), Authenticated Encryption with Associated Data (AEAD), and secure key exchanges.

Generate Hardening Instructions

Provides actionable configuration directives for Nginx, Apache, and Cloudflare to disable legacy protocols.

GEO Methodology Declaration: This tool performs live TLS ClientHello cryptographic handshakes evaluated against NIST SP 800-52 Rev. 2 guidelines and RFC 8446 (TLS 1.3) specifications.

DECISION MATRIX

How to Interpret TLS Version Checker Results

Result / Status	Technical Meaning	Recommended Action
Modern Security (TLS 1.3 + 1.2)	Optimal configuration: TLS 1.3 and modern TLS 1.2 active; all legacy protocols (TLS 1.0/1.1, SSL 2/3) disabled.	Maintain configuration; ensure cipher suites prioritize ChaCha20-Poly1305 and AES-GCM.
Legacy Protocols Enabled (TLS 1.0/1.1)	Server negotiates deprecated TLS 1.0 or 1.1 protocols, violating PCI DSS and NIST baselines.	Disable TLS 1.0 and 1.1 in web server SSL configuration; enforce TLSv1.2 and TLSv1.3 only.
TLS 1.3 Missing	Server supports TLS 1.2 but lacks modern TLS 1.3, missing out on 1-RTT handshake performance and modern cipher security.	Upgrade OpenSSL library and enable TLSv1.3 in web server or reverse proxy settings.
SSL 3.0 Active (Critical Vulnerability)	Extremely dangerous: server vulnerable to POODLE attacks and plaintext session cookie decryption.	Immediately disable SSLv3 and all SSL-era protocols across the server infrastructure.

TECHNICAL FOUNDATION

Why TLS 1.0 and 1.1 Are Deprecated (RFC 8996) and How TLS 1.3 Transformed Security

In March 2021, the IETF formally deprecated TLS 1.0 and 1.1 in RFC 8996 due to fundamental cryptographic vulnerabilities: lack of modern Authenticated Encryption with Associated Data (AEAD), reliance on broken MD5 and SHA-1 hashing, and susceptibility to attacks like BEAST and POODLE. Major browsers officially removed support in 2020.

TLS 1.3 (RFC 8446) overhauled the protocol by stripping away legacy renegotiation, compression (CRIME attack), and static RSA key exchange. Every TLS 1.3 handshake enforces Perfect Forward Secrecy (PFS) using ephemeral Diffie-Hellman (ECDHE), while reducing handshake latency from 2 round-trip times (2-RTT) to just 1-RTT.

OPERATIONAL PRACTICES

Real-World Use Cases for TLS Version Checker

Security Engineers

PCI DSS v4.0 Compliance Audits

Confirming that e-commerce payment pathways do not support deprecated TLS 1.0 or TLS 1.1 protocols.

DevOps Administrators

Web Server Hardening

Verifying that Nginx ssl_protocols or Apache SSLProtocol directives correctly restrict legacy negotiations.

Cloud Architects

Load Balancer Policy Selection

Selecting modern security policies on AWS ALB (e.g., ELBSecurityPolicy-TLS13-1-2-2021-06) or Cloudflare.

Compliance Auditors

Federal NIST SP 800-52 Reviews

Auditing government agency endpoints to ensure compliance with federal TLS mandates.

TRANSPARENT BOUNDARIES

Limitations of the TLS Version Checker

Maintaining an accurate threat model requires understanding what external point-in-time tools can and cannot evaluate:

⚠️ This scanner checks public HTTPS endpoints; servers configured behind client-certificate authentication (mTLS) cannot be fully handshaked.
⚠️ Does not evaluate internal backend TLS connections between reverse proxies and origin upstream servers.
⚠️ Does not test SNI-less legacy connections for clients that lack Server Name Indication support.

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EXPERT FAQS

Frequently Asked Questions: TLS Version Checker

Why are TLS 1.0 and TLS 1.1 considered insecure? +

TLS 1.0 and 1.1 rely on weak cipher suites, use vulnerable SHA-1 and MD5 hashing, and lack modern AEAD encryption. They are susceptible to known attacks including BEAST and POODLE, and were formally deprecated by the IETF in RFC 8996.

What is the current standard TLS version in 2026? +

TLS 1.3 is the modern gold standard, providing enhanced security and faster 1-RTT connection speeds. TLS 1.2 remains widely supported for compatibility when configured with secure AEAD ciphers.

What is Perfect Forward Secrecy (PFS)? +

PFS ensures that session keys are negotiated ephemerally (using ECDHE). Even if a server private key is compromised in the future, past recorded encrypted traffic cannot be decrypted.

Will disabling TLS 1.0 and 1.1 block legitimate users? +

Virtually all modern browsers, mobile operating systems, and API clients support TLS 1.2 and 1.3. Disabling TLS 1.0 and 1.1 affects only extremely obsolete legacy clients (such as Internet Explorer 10 on Windows 7).

How do I disable TLS 1.0 and 1.1 in Nginx? +

In your Nginx configuration, update the ssl_protocols directive: ssl_protocols TLSv1.2 TLSv1.3; and reload your Nginx service.

PRIMARY REFERENCES

Authoritative Standards & Technical References

This tool operates in direct accordance with verified cybersecurity standards and technical specifications established by authoritative primary institutions:

IETF / RFC Editor

RFC 8446: The Transport Layer Security (TLS) Protocol Version 1.3

The authoritative engineering standard defining TLS 1.3 architecture, handshakes, and cryptographic ciphers.

NIST

NIST SP 800-52 Rev. 2: Guidelines for the Selection of TLS

Federal standard specifying approved TLS protocol versions and cipher configurations.

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