Thirteen terabytes of Steam depot data, reportedly spanning from 2003 to 2013, has leaked online within the past 24 hours. The leak has been made publicly available via a torrent file, and those investigating the contents have reported that it contains beta builds for thousands of games, including Portal 2, Left 4 Dead 2, Dragon Age: Origins, and Batman: Arkham Asylum.
Exactly who obtained the leaked data in question is currently unconfirmed, but the leak appears to be very real and can easily be found online. Given the size of the leak, it’s taken people some time to sort through it all, but a list of the contents discovered so far is being actively cataloged on GitHub.
It’s important to note that the “Steam2” leak, as it’s been dubbed, contains data spanning from 2003 to 2013. Considering how much video game file sizes have ballooned in the last decade, 13 terabytes of pre-2014 data is a bigger deal than some might initially assume.
(1/2) That Valve leak that just happened a few hours ago might actually be one of the biggest video game leaks of all time. It will be interesting to see how this all goes down.
Basically a shit ton of beta builds uploaded to Steam in-between 2003 – 2013 has leaked.
— AestheticGamer aka Dusk Golem (@AestheticGamer1) August 30, 2026
With this in mind, there’s a lot of unconfirmed info going around out there at the moment. This is essentially my way of warning you that you should take any purported Half-Life 3 “leaks” with an extra carton of salt for the next week or two.
However, there are a couple of interesting things that have already been confirmed, such as the existence of a Portal 2 beta.
Someone leaked 12 TB of Valve’s internal builds and game assets from 2003 to 2013. This includes early versions of Portal 2, Left 4 Dead, CS:GO, F-Stop and potentially EP3. The community is still researching everything, so the next few days might be insane… There’s a Weaponizer… pic.twitter.com/Sg7OqJjL2X
— Gabe Follower (@gabefollower) August 29, 2026
A few videos of people playing through it have started cropping up online, which is likely why Elan Ruskin, an ex-Valve developer who worked on the likes of Half-Life 2: Episode Two, Left 4 Dead 2, Portal, and Portal 2, chose to address the existence of the “prerelease” builds of Portal 2 and Left 4 Dead 2 in a post on X earlier today.
My condolences to anyone who wastes time playing prerelease versions of P2 or L4D2. Listen, every good idea we had went into the final thing we shipped, and anything not in the final version was not a good idea. https://t.co/S4mTllUy3F
— Elan Ruskin (@despair) August 30, 2026
According to Gabe Follower on X, who was seemingly the first person to publicize the leak, the data in question was obtained from a “publicly accessible endpoint” on Steam’s servers. In this context, an “endpoint” is jargon for a URL that users can send requests to and receive responses from.
From what I understand, endpoints are usually publicly available anyway, but require a form of authorization to access. With that in mind, if Gabe Follower’s sources are correct, I am curious if this means that the data in the leak has something to do with the release of SteamOS in 2013.
According to Gabe Follower, the fact that the “Steam2” depot data only goes up to 2013 may have something to do with Valve switching “to the new storage system” in 2013. For context, Steam was released on September 12, 2003, and SteamOS 1.0 was released in December 2013, which coincidentally lines up with the start and end dates of the Steam2 depot leak contents.