TLS vs SSL is a comparison between two protocols that encrypt the connection between your browser and a website. SSL came first, in the 1990s. TLS replaced it and does the job more safely and more quickly. Yet people still say "SSL" when they mean TLS, which is why beginners so often get confused.
This guide looks at each protocol in turn, then at the handshake they share. After that it compares them on security, speed, cost and ease, and real-world support. It ends with a simple rule for choosing. By the end, you'll know what is actually behind the padlock in your address bar, and what to switch on for your own site.
- SSL was Netscape's 1990s protocol. It is now deprecated and unsafe.
- TLS is the open IETF standard that replaced SSL in 1999. The current version is TLS 1.3.
- TLS beats SSL on security, speed, cost and ease, and browser support.
- An "SSL certificate" is just an old label. The same certificate works with TLS.
- Rule of thumb: use TLS 1.3, keep TLS 1.2 for older devices, and never use SSL.
- 0:00Intro
- 0:27Meet SSL and TLS
- 1:23SSL: the 1990s original
- 2:19TLS: SSL's open successor
- 3:18The handshake behind the padlock
- 4:13Why SSL is no longer safe
- 5:01TLS 1.3 starts faster
- 5:50The SSL certificate mix-up
- 6:43Who still speaks SSL?
- 7:30You're launching a small website
- 8:10Pick TLS, every time
- 8:56What changed, and why
- 9:32Use TLS; SSL is just a name
What is SSL? The 1990s original
In the early web, everything travelled as plain text. Anyone along the network path could read your passwords and messages. SSL was created to fix that. The name stands for Secure Sockets Layer. It is "secure" because it encrypts, and "sockets" refers to the connections programs use to talk over a network. It is a "layer" because it sits between your application and that connection.
SSL was built at Netscape, the company behind one of the first popular web browsers. The goal was to let people shop and log in online without exposing their details. Two versions were released publicly, SSL 2.0 and 3.0. Each one patched problems in the version before, but the basic design kept some old weaknesses.
Today SSL is officially deprecated. You shouldn't run it anywhere. It now matters mainly as history, and as a name that never went away.
- Full name: Secure Sockets Layer
- Created at Netscape in the 1990s
- Public versions: 2.0 and 3.0
- Status: deprecated and unsafe
What is TLS? SSL's open successor
TLS stands for Transport Layer Security. It protects data while it travels, it sits between your application and the network just as SSL did, and security is its whole purpose. The key difference is ownership. No single company controls TLS. The Internet Engineering Task Force (IETF) published it in 1999 as an open standard, so everyone could build on the same public rules.
The first version of TLS was essentially an upgraded SSL 3.0 under a new name. It then improved through versions 1.1 and 1.2, up to TLS 1.3, which is current today. Each version removed weak options that attackers had learned to exploit. TLS 1.3 is also simpler and faster than earlier versions.
So TLS isn't really a rival to SSL. It is SSL grown up and repaired, run in the open rather than by one company.
- Full name: Transport Layer Security
- Published by the IETF in 1999
- Current version: TLS 1.3
- Status: secures the web today
How the handshake behind the padlock works
SSL and TLS both start a connection in the same way, with a short exchange called a handshake. Before any web page is sent, the browser and the server set up a private channel. The browser opens with "hello" and a list of the encryption methods, or ciphers, it supports. The server replies with its own hello plus its certificate.
Next, the browser sends a key share so both sides can build the same secret key. The key itself is never sent across the network. The server then signals that it has finished, and from that point only encrypted data flows.
The certificate step is what earns the padlock. Your browser checks that the certificate was signed by a trusted authority and matches the site's name. If either check fails, you see a warning instead. SSL and TLS follow this same plan. They differ in how safely and how quickly they carry it out.
- Browser → Server: hello, plus supported ciphers
- Server → Browser: hello, plus certificate
- Browser → Server: key share
- Server → Browser: finished
- From then on: encrypted data only
Security: why SSL is no longer safe
Security is the comparison that matters most. A protocol is only as strong as its weakest option, and SSL's options have aged badly. SSL relies on old, weak ciphers. TLS 1.2 and 1.3 use modern ones.
Real attacks have exposed the gap. SSL 3.0 is broken by an attack called POODLE, which can leak secrets such as login cookies. TLS was designed to resist attacks like this. TLS 1.3 goes a step further and removes old options completely, so an attacker can't trick a server into falling back to a weaker method.
The result is one-sided. SSL is unsafe to use, and TLS is the recommended choice. If you care about security at all, and every website should, SSL is out.
- Ciphers: SSL uses old, weak ones; TLS 1.2/1.3 use modern ones
- Attacks: SSL 3.0 is broken by POODLE; TLS is built to resist known attacks
- Status: SSL is unsafe; TLS is recommended
Speed: TLS 1.3 needs only one round trip
You might expect stronger security to make connections slower. With TLS 1.3, it's the other way round. Every handshake message has to cross the network, and each round trip adds a wait before your page starts to load.
Older handshakes, including SSL and TLS 1.2, need two full round trips before any real data can move. TLS 1.3 needs only one, often written as 1 RTT, because the browser sends its key share right away instead of waiting. That means a secure connection is ready in about half the waiting time of the older design.
The difference is easiest to notice on phones. On a slow mobile network, every round trip counts. So TLS wins on speed too, and its extra safety costs you no time.
Cost and ease: the "SSL certificate" mix-up
This is where most beginners get stuck. When you set up a website, your hosting panel probably offers an "SSL certificate". That sounds like you are choosing old technology, but you aren't. There is no separate TLS certificate to buy instead. It is the same certificate either way.
A certificate proves who the site is, and it works with whichever protocol the server uses. The "SSL" in the name is left over from the 1990s, and the industry never changed it. Hosting companies, certificate sellers and even engineers still use the old word out of habit.
Getting one is also easy and free. Let's Encrypt, a nonprofit, issues trusted certificates at no cost, and many hosts set them up for you automatically. On cost and ease, TLS wins without effort.
Do browsers still support SSL?
A protocol only works if both ends agree to use it, so support settles the question in practice. Standards bodies have formally retired SSL, and modern browsers have removed it completely. If a browser reaches a site that only offers SSL, the connection is refused, usually with an error page. If the site uses TLS, it connects and you see the padlock.
The early TLS versions, 1.0 and 1.1, have been switched off as well. Meanwhile, banks, shops, email and apps all depend on modern TLS, which secures most of the web's traffic today. On support, TLS is the only real option left.
Setting up TLS on a small website
Here is how this works for a small site of your own. Most hosting companies use the same basic setup, so these steps should look familiar. Start by getting a free certificate from Let's Encrypt. Many hosts will do this for you.
Next, install the certificate on your web server and turn on TLS 1.3 and TLS 1.2. Then check that the older protocols are turned off: SSL 2.0, SSL 3.0, TLS 1.0 and TLS 1.1. Your visitors get a fast, modern, secure connection, and broken protocols can't slip back in. The whole setup costs nothing except a few minutes.
- Get a free certificate from Let's Encrypt
- Install it on your web server
- Enable TLS 1.3 and TLS 1.2
- Disable SSL 2.0, SSL 3.0, TLS 1.0 and TLS 1.1
TLS or SSL: which should you pick?
After comparing security, speed, cost, ease and support, there is nothing left to weigh. The rule of thumb is short: use TLS 1.2 or 1.3. When someone says SSL today, they almost always mean TLS. SSL is just the old name.
Make TLS 1.3 your default. It is the fastest and safest option, and every modern browser supports it. Keep TLS 1.2 enabled if some older devices still need to connect. With modern ciphers, it is still considered safe. Never use SSL, for any reason. It is broken, browsers refuse it, and it offers nothing TLS doesn't. This rule applies to any site, app or server you build. Only the version details change.
- First choice: TLS 1.3
- Keep for older devices: TLS 1.2
- Never: SSL 2.0 or 3.0
Key takeaways
- SSL was Netscape's 1990s original. TLS is its IETF successor, now at version 1.3.
- Both use the same handshake: check the certificate, agree on keys, then encrypt.
- TLS is safer than SSL, and TLS 1.3 is faster too, needing one round trip instead of two.
- An "SSL certificate" works with TLS. Only the name is outdated.
- Use TLS 1.2 or 1.3, and switch off SSL and TLS 1.0/1.1.
Frequently asked questions
Is TLS the same as SSL?
They do the same job, but they are not the same protocol. TLS is the successor to SSL. Its first version was an upgraded SSL 3.0, and it has been improved and made safer with each version since.
Do I need to buy an SSL certificate or a TLS certificate?
It's the same certificate either way. "SSL certificate" is a leftover name, and the certificate works with TLS. Let's Encrypt issues trusted certificates for free, and many hosts install them automatically.
Why is SSL considered unsafe?
SSL relies on old, weak ciphers, and SSL 3.0 is broken by the POODLE attack, which can leak secrets such as login cookies. It has been formally deprecated, and modern browsers refuse to use it.
Is TLS 1.2 still safe to use?
Yes. When it is configured with modern ciphers, TLS 1.2 is still considered safe. TLS 1.3 should be your default, and TLS 1.2 is mainly there for older devices.
Why is TLS 1.3 faster than older versions?
TLS 1.3 completes its handshake in one round trip instead of two, because the browser sends its key share right away. That roughly halves the wait before a secure connection is ready, which is especially noticeable on slow mobile networks.
Should I turn off TLS 1.0 and 1.1?
Yes. Like SSL, these early TLS versions have been switched off in modern browsers. Enable only TLS 1.2 and 1.3 on your server.
