Approximately 12TB of data has been reportedly extracted from Steam, which apparently encompasses everything that was published on the platform between 2003 and 2013.

According to Valve-related content creator Gabe Follower, the data has allegedly been gathered via a publicly accessible endpoint, and the process to collect it involved no actual hacking. Valve transitioned to a different storage system in 2013, which is why the data cuts off at this point.

Gabe Follower notes this data includes the entire Steam library from the period between 2003 and 2013 – not just Valve games. The 12TB of data is said to contain both complete games and beta versions of games, and a variety of early and unseen prototype versions of games that were placed on Steam sometime within that 10-year period have already been uncovered by archivists, enthusiasts, and other interested parties. For instance, those digging have found a build of Left 4 Dead from several months prior to its actual release which features a different HUD, voice lines which never featured in the retail version, and sections of the map that were subsequently altered.

With the sheer size of the leaked data pile, it’s likely more such information will be revealed as people search through it.

Valve has not commented on the data leak at this stage.

Luke is a Senior Editor on the IGN reviews team. You can track him down on Bluesky @mrlukereilly to ask him things about stuff.