Every https:// connection is secured by TLS — and the version your servers speak quietly affects both speed and security. TLS 1.3, finalised in 2018, is now the standard, and it's a rare upgrade that makes things faster and safer at the same time. Here's what changed from 1.2.
A quick recap of TLS
TLS is the protocol that encrypts web traffic (the "S" in HTTPS). Before any data flows, the client and server perform a handshake — agreeing on a version and cipher, exchanging keys, and verifying the server's certificate. The version they use shapes how fast and secure that handshake is.
What TLS 1.3 changed
TLS 1.3 improved security largely by removing things — dropping old, weak options that had caused vulnerabilities for years.
| Area | TLS 1.2 | TLS 1.3 |
|---|---|---|
| Handshake round trips | Two (slower to set up) | One (faster) |
| Resumed connections | Round trip needed | "0-RTT" — near-instant |
| Old/weak ciphers | Still allowed | Removed entirely |
| Default security | Depends on config | Secure by default |
Faster handshakes
TLS 1.2 needed two round trips to set up a secure connection; TLS 1.3 cut that to one. On a high-latency connection (mobile, distant servers), that saved round trip is real, noticeable speed — it lowers your TTFB for first connections.
More secure by design
TLS 1.2's flexibility was also its weakness: it supported old ciphers and options that, misconfigured, opened holes (many famous TLS attacks targeted these). TLS 1.3 removed the legacy cruft — fewer options means fewer ways to get it wrong. It's secure by default rather than secure-if-configured-carefully.
The neat part: TLS 1.3 is faster because it's simpler, and more secure because it's simpler. Stripping out the old, weak options improved both at once.
What about TLS 1.0 and 1.1?
Those older versions are deprecated and unsafe — modern browsers reject them. If a server only offers TLS 1.0/1.1, up-to-date clients refuse to connect (a cause of handshake failures). They should be disabled everywhere.
What you should do
You don't implement TLS yourself, but you should make sure your servers and CDN are configured well:
- Support TLS 1.2 and 1.3. 1.3 for speed and security, 1.2 for any older clients that need it.
- Disable TLS 1.0 and 1.1. They're insecure and trigger failures with modern clients.
- Keep certificates valid. TLS version means nothing if your certificate has expired — that breaks the handshake regardless.
- Send the full chain. A common handshake failure is a missing intermediate certificate.
A monitoring angle
Your TLS setup can drift — a renewal changes the chain, a config update disables a needed version. Monitoring the TLS connection (that the handshake completes, the chain is valid, and the certificate isn't near expiry) catches these before they become a total HTTPS outage.
The bottom line
| In one line | |
|---|---|
| TLS 1.3 | One-round-trip handshake — faster than 1.2's two. |
| Security | More secure by removing old, weak options. |
| TLS 1.0/1.1 | Deprecated and unsafe — disable them. |
| You | Support 1.2 + 1.3, valid certs, full chain. |
TLS 1.3 is a quiet win: enable it (almost always a toggle at your server or CDN) and your HTTPS gets both faster and safer, with fewer ways to misconfigure. Just keep your certificates and chain healthy underneath it.
Related: How HTTPS works, SSL certificate expiry; check any site's TLS with the free SSL checker.