SSL and TLS Explained: What are the key differences?

First, let’s define the terms. SSL stands for Secure Sockets Layer, while TLS stands for Transport Layer Security. Both SSL and TLS are protocols that encrypt data that is transmitted over the internet. This encryption helps to protect sensitive information from being intercepted by hackers or other malicious actors.

So how does encryption work in simple terms? You can think of sending information over the internet like sending a letter in the mail. If you were to send a letter without any encryption, anyone who intercepted the letter could read its contents. However, if you were to use a code to encrypt the letter, only the intended recipient would be able to decode and read the message.

SSL and TLS work in a similar way. When you visit a website, your web browser and the website’s server establish an SSL or TLS connection. This connection is like the code used to encrypt the letter. It ensures that any data that is transmitted between your browser and the website’s server is encrypted and therefore secure.

Differences between SSL and TLS

So, what are the key differences between SSL and TLS? Essentially, TLS is the successor to SSL. SSL was first developed in the 1990s by Netscape. SSL became increasingly vulnerable to security vulnerabilities and has since been replaced by newer, more secure protocols like TLS. In fact, the latest version of TLS (TLS 1.3) is considered to be more secure than the latest version of SSL (SSL 3.0).

In Summary, here are the differences between SSL and TLS:


  • An outdated security protocol for encrypting data transmitted over the internet
  • Developed by Netscape in the 1990s
  • Has known vulnerabilities that make it less secure than TLS
  • No longer widely used, as it has been largely replaced by TLS


  • A modern and widely used security protocol for encrypting data transmitted over the internet.
  • Developed as a successor to SSL by the Internet Engineering Task Force (IETF).
  • More secure than SSL and has stronger encryption algorithms.
  • Continuously updated with new versions to address new security threats and vulnerabilities.
  • Includes additional security features such as Perfect Forward Secrecy (PFS) and Server Name Indication (SNI).
  • Supported by most web browsers and used by the majority of websites for secure communication

Related: How to check for your SSL Certificate chain and fix issues

What about SSL Certificates and HTTPS?

While TLS is now the preferred protocol, SSL remains a widely recognized term in the context of website security. Many people still refer to SSL certificates, even though what they are actually referring to is a TLS certificate. This is likely due to the fact that SSL was the original protocol and remained the standard for many years. Because of their close similarities and to avoid confusion, TLS and SSL are usually written as SSL/TLS.

HTTPS (Hyper Text Transfer Protocol Secure) appears in the URL when a website is secured by an SSL certificate.┬áToday, browsers hide the “https://” segment of the website URL. A padlock icon is instead used to signal that a website is being secured by an SSL/TLS certificate.

So, why does all of this matter for website owners and administrators? Essentially, SSL and TLS are essential tools for protecting your website and your users’ data from cyberattacks. When you install an SSL or TLS certificate on your website, you’re taking an important step towards securing your site and ensuring that any data that is transmitted over the internet is encrypted and protected.