How to use TLS Version Checker
The TLS Version Checker tells you exactly which TLS protocol versions a server will accept, from legacy TLS 1.0 and 1.1 through to the modern TLS 1.2 and 1.3. It works by attempting a real handshake pinned to each version in turn and reporting which ones complete. Knowing a server’s supported versions matters for security and compliance: TLS 1.0 and 1.1 are deprecated and disabled by every major browser, and standards such as PCI DSS require them to be turned off. At the same time, you want to confirm TLS 1.2 and 1.3 are available so modern clients connect securely. This tool gives you a clear, version-by-version answer in seconds.
- Enter the hostname you want to test, such as example.com.
- Click Check to probe each TLS version on port 443.
- Review which versions are supported, deprecated, or unavailable.
- Confirm TLS 1.2 and 1.3 are present and 1.0/1.1 are off.
- Reconfigure the server if deprecated versions are still enabled.
How the version probe works
For each protocol version the tool opens a TCP connection to port 443 and starts a TLS handshake with both the minimum and maximum version pinned to that single value. If the server completes the handshake, the version is supported; if it refuses or the handshake fails, it is reported as unavailable. Pinning each version individually is the most reliable way to enumerate support, because a normal connection only reveals the single highest version both sides agree on rather than the full set the server allows.
Which TLS versions are safe today
TLS 1.2, published in 2008, remains secure when configured with strong cipher suites and is still the most widely deployed version. TLS 1.3, finalized in 2018, is faster and drops legacy cryptography entirely, and should be enabled wherever possible. TLS 1.0 and 1.1, by contrast, have known weaknesses, were deprecated by the IETF in 2021, and are rejected by current browsers — leaving them enabled is a compliance failure and a needless risk. Aim for TLS 1.2 and 1.3 on, everything older off.
| Version | Status |
|---|---|
| TLS 1.3 | Recommended |
| TLS 1.2 | Secure |
| TLS 1.1 | Deprecated |
| TLS 1.0 | Deprecated / insecure |
Glossary
- TLS
- Transport Layer Security, the protocol that encrypts HTTPS and other connections.
- Handshake
- The negotiation where client and server agree on a TLS version and keys.
- TLS 1.3
- The latest TLS version — faster and more secure than its predecessors.
- Cipher suite
- The set of algorithms used to secure a TLS connection.
- PCI DSS
- A payment-industry standard that requires deprecated TLS versions be disabled.
Related reading
Frequently Asked Questions
Why use TLS Version Checker?
- See every TLS version a server accepts at a glance
- Confirm modern TLS 1.2 and 1.3 support is enabled
- Catch deprecated TLS 1.0 and 1.1 that should be disabled
- Verify compliance posture before an audit or pen test
Common use cases
- Confirm a server has disabled insecure TLS 1.0 and 1.1 for PCI compliance
- Verify TLS 1.3 is enabled after a web-server or load-balancer upgrade
- Audit a vendor’s endpoint before integrating with it
- Diagnose why an old client cannot negotiate a connection
- Document the TLS posture of your estate during a security review
Get weekly tool tips & updates
New tools, power-user tips, and productivity hacks — delivered free every Friday.
No spam, ever. Unsubscribe with one click.
Related Network & DNS
SSL Certificate Checker
Check SSL/TLS certificate validity, issuer, expiry date, and remaining days for any domain to prevent HTTPS outages and certificate trust errors.
SSL Certificate Decoder
Decode SSL/TLS PEM certificates to inspect subject, issuer, SANs, validity dates, key metadata, and fingerprints for faster troubleshooting.
DNSSEC Checker
Check whether a domain has DNSSEC enabled by validating DNSKEY and DS records. Confirm DNS integrity signals and reduce spoofing risk.
HTTP Headers Checker
View HTTP response headers for any URL. Check status codes, security headers, caching, redirects, and server details instantly. Free and private.
CSR Decoder
Decode and inspect Certificate Signing Requests (CSR). View subject details, public key size, and algorithm from PEM CSR.
DNS Lookup Tool
Look up DNS records for any domain — A, AAAA, MX, NS, TXT, CNAME, SOA, and CAA records. Free, instant results pulled from authoritative nameservers.
Explore all Network & DNS.