Is SSL the same as TLS?

No. SSL is the older, deprecated protocol. TLS is its successor. When people say 'SSL' today, they almost always mean TLS. All SSL versions have known vulnerabilities and should not be used.

What TLS version should I use?

TLS 1.3 is the current standard. TLS 1.2 is still acceptable. Anything older (TLS 1.0, 1.1, SSL 2.0, SSL 3.0) is deprecated and insecure.

Do I need an SSL certificate if I use Vercel or Netlify?

These platforms provide TLS certificates automatically. You don't need to buy or configure one yourself.

SSL vs TLS: What's the Difference and Why It Matters

The short version

SSL (Secure Sockets Layer) and TLS (Transport Layer Security) are protocols that encrypt the connection between a browser and a server. That padlock icon in your browser's address bar? That's TLS at work.

Here's the thing: SSL is dead. Every version of SSL has known security flaws. What we actually use today is TLS. When someone says "SSL certificate," they mean a certificate used with TLS. The name stuck, the protocol didn't.

A brief history

SSL 2.0 (1995): First public release. Fundamentally broken. Never use.
SSL 3.0 (1996): Fixed some issues, but still vulnerable (see: POODLE attack).
TLS 1.0 (1999): First TLS version. Deprecated since 2020.
TLS 1.1 (2006): Minor improvements. Also deprecated.
TLS 1.2 (2008): Still widely used and considered secure.
TLS 1.3 (2018): Current standard. Faster handshake, stronger security. Defined in RFC 8446.

If your server still supports TLS 1.0 or 1.1, you're serving insecure connections. Major browsers have dropped support for these versions.

What TLS actually does

When you visit a site over HTTPS, TLS does three things:

Encryption: Your data is encrypted in transit. Nobody on the network can read it.
Authentication: The server proves its identity using a certificate. Your browser verifies this certificate against trusted Certificate Authorities.
Integrity: The data can't be modified in transit without detection.

Without TLS, everything you send and receive (passwords, credit cards, personal data) travels as plain text. Anyone on the same network can read it.

TLS 1.3: why it matters

TLS 1.3 is a significant improvement over 1.2:

Faster: The handshake takes one round trip instead of two. With 0-RTT resumption, returning visitors connect even faster.
More secure: Removed support for older, weaker cipher suites. No more RSA key exchange, no more CBC mode ciphers.
Simpler: Fewer options means fewer ways to misconfigure it.

Qualys SSL Labs is the standard tool for testing your TLS configuration. It grades your setup from A+ to F.

Common mistakes

Still supporting TLS 1.0/1.1. These protocols have known weaknesses. Disable them. Every major browser stopped supporting them by 2020.

Using weak cipher suites. Even with TLS 1.2, you can choose weak ciphers. The SSL Labs test will flag these. Stick to AEAD cipher suites (like AES-GCM or ChaCha20).

Expired certificates. Your TLS certificate has an expiration date. If it expires, browsers show a scary warning page and users leave. Use Let's Encrypt for free, auto-renewing certificates.

Mixed content. Your page loads over HTTPS, but some resources (images, scripts) load over HTTP. This undermines TLS because those HTTP resources can be intercepted. The MDN mixed content guide explains how to find and fix these issues.

Not enabling HSTS. TLS encrypts the connection, but without HSTS, a user's first request might still happen over HTTP. The two go hand in hand.

What you should do

Make sure your server supports TLS 1.2 and 1.3.
Disable TLS 1.0, 1.1, and all SSL versions.
Test with SSL Labs. Aim for an A or A+ grade.
Set up automatic certificate renewal with Let's Encrypt.
Enable HSTS so browsers never connect over plain HTTP.

If you're on Vercel, Netlify, or Cloudflare, most of this is handled for you. But it's still worth checking.

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