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TLS (Transport Layer Security)

Also known as: Transport Layer Security, SSL, HTTPS encryption

The technology that scrambles data travelling between your website and your visitors so nobody can read or tamper with it in transit.

What it is

TLS, short for Transport Layer Security, is the technology that puts the “s” in https and the padlock in the address bar. When a visitor connects to your site, TLS scrambles everything they send and receive — logins, card numbers, form entries — so that anyone listening on the network in between sees only gibberish. “SSL” is the older name for the same idea; TLS is the modern, secure version.

There are different versions of TLS, and like any software the older ones get retired as weaknesses are found. Today the healthy versions are TLS 1.2 and TLS 1.3.

Why it matters to your business

Without TLS, data travels in plain readable text, and someone on the same coffee-shop Wi-Fi or compromised network can quietly capture it. With TLS, that same data is unreadable to them.

But it’s not just on/off. If your site still allows old, retired versions of TLS, it’s leaving a weaker door open that attackers can target — even while the padlock still appears. Running only current versions keeps the protection genuinely strong, and keeps you aligned with what payment and data rules increasingly expect.

How to tell / what to do

Our free checker reports which TLS versions your site accepts and flags any outdated ones that should be switched off. If it finds weak versions, the TLS fix guide explains how to tighten the settings. It’s free and invisible to your visitors — their experience doesn’t change, only the safety underneath.

Want to fix this on your own domain? See the free guide →