What is Tor?
Tor is a separate, secure internet. To quote Wikipedia(new window):
“Tor directs Internet traffic through a free, worldwide, volunteer network consisting of more than seven thousand relays to conceal a user’s location and usage from anyone conducting network surveillance or traffic analysis.”
Tor was originally developed in the 1990s and today is used worldwide by people who need to browse the internet anonymously. For example, it is commonly used by journalists and activists operating under repressive regimes. Special websites, called onion sites, can only be accessed via Tor and require you to install the Tor Browser on your device (or access the Tor network with Tor over VPN(new window)).
Tor for Desktop
The easiest way to browse onion websites is to download Tor Browser. Tor Browser is almost the same as the popular Firefox web browser, but it has built-in support for Tor. Simply downloading Tor Browser will let you visit onion websites right away.
Tor for iOS and Android
The Tor Project endorses the following mobile apps for browsing onion sites on mobile:
3. Visit Our Onion Site
Once you can access Tor, you can visit our onion site here:
For more information about Proton Mail’s onion site, you can also read our Tor announcement blog post.