TLS Version Checker

Test which TLS versions your server supports. Verify TLS 1.3 and TLS 1.2 compatibility.

About SSL Certificate Checker

Comprehensive SSL/TLS certificate analyzer that validates certificate chains, checks expiration dates, and verifies hostname matching from multiple global locations.

Key Features

Multi-region SSL validation

Certificate chain verification

Expiration monitoring

TLS version detection

Hostname validation

Also Available via API & MCP Server

Automate ssl certificate checker checks in your CI/CD pipelines or run them directly from your AI coding agent.

REST API

Single endpoint, JSON response. Integrate into any language or platform.

cURL

curl -X POST https://probeops.com/api/v1/run \
  -H "X-API-Key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"tool": "ssl_check", "target": "example.com"}'

Learn more about the API

MCP Server

Works with Claude Code, Cursor, Windsurf, and any MCP-compatible IDE.

Claude Code

> Check the ssl certificate checker for example.com

Claude uses the probeops_ssl_check tool to run
the check from 6 global regions and returns
structured results.

Learn more about the MCP Server

TLS (Transport Layer Security) version determines the encryption protocols your server uses. TLS 1.0 and 1.1 are deprecated and blocked by all major browsers since 2020. Modern sites should support TLS 1.2 and TLS 1.3 for optimal security and performance.

Our TLS checker identifies which protocol versions your server accepts and highlights outdated configurations. TLS 1.3 offers faster handshakes and stronger security—verify your server supports it from all global regions.

**Methodology:** TLS handshake testing each protocol version (1.0, 1.1, 1.2, 1.3) from 6 regions to identify supported versions.

Common SSL Errors & How to Fix Them

4 relevant issues

Modern browsers block TLS 1.0/1.1 connections. May work on old systems but fail on new ones.

How to Fix

Disable TLS 1.0 and 1.1 on your server. Enable TLS 1.2 and 1.3. For Apache: SSLProtocol -all +TLSv1.2 +TLSv1.3. For Nginx: ssl_protocols TLSv1.2 TLSv1.3;

tls 1.0tls 1.1protocol versionssl version

Server supports TLS 1.2 but not TLS 1.3. Missing performance and security benefits.

How to Fix

Upgrade your web server to a version supporting TLS 1.3 (OpenSSL 1.1.1+, nginx 1.13+, Apache 2.4.37+). Update ssl_protocols to include TLSv1.3. Verify with this tool after configuration.

tls 1.3no tls 1.3upgrade tls

Connection works but uses outdated encryption (DES, RC4, export ciphers).

How to Fix

Configure strong cipher suites only. Recommended: ECDHE+AESGCM:ECDHE+CHACHA20. Disable CBC mode ciphers if possible. Use Mozilla SSL Configuration Generator for your server type.

weak cipherinsecure cipherencryption strength

Connection fails before exchanging any data. May be regional or affect specific clients.

How to Fix

Check server firewall allows port 443. Verify SNI is configured correctly for multiple domains. Ensure cipher suites match client capabilities. Check for IP blocking or rate limiting.

handshake failuressl connection failedsni

See all SSL errors →

Frequently Asked Questions

4 relevant questions

Modern servers should support TLS 1.2 and TLS 1.3. TLS 1.3 is the latest standard with improved security and faster handshakes. TLS 1.0 and 1.1 are deprecated and blocked by major browsers since 2020. If our tool shows TLS 1.0/1.1, update your server configuration immediately to maintain security and browser compatibility.

TLS 1.3 offers: 1) Faster connections with 1-RTT handshakes (vs 2-RTT in TLS 1.2), 2) Zero-RTT resumption for returning visitors, 3) Removed insecure algorithms (RSA key exchange, CBC ciphers), 4) Forward secrecy mandatory, 5) Encrypted handshake hiding more metadata. Most modern servers and browsers support TLS 1.3 since 2018.

For Nginx: ssl_protocols TLSv1.2 TLSv1.3; For Apache: SSLProtocol -all +TLSv1.2 +TLSv1.3. For IIS: Use registry keys or IIS Crypto tool. After changes, restart your web server and test with this tool to confirm old versions are disabled. Note: This may break very old clients (IE 10, Android 4.x).

Our health score (0-100) weighs: certificate validity across all tested regions (60%), days until expiry (20% - higher scores for >60 days), TLS version (10% - TLS 1.3 scores highest), and cipher strength (10% - 256-bit encryption preferred). A score of 80+ indicates excellent certificate health. Below 50 requires immediate attention.

See all SSL FAQs →

How to Check SSL Certificate ExpiryStep-by-step guide with examples and troubleshooting tips