Portal F-Stop Leak: Canceled Valve Prequel Is Now Playable

By GameDrop Staff · Nov 01, 2026 · Leaks · 1 min read

Chamber from Portal and Portal 2 showing a test room — Image: Valve

A nearly complete, playable build of F-Stop, Valve's canceled camera-based Portal prequel, has been pieced together by leakers, The Verge reported on November 1, 2026. This is a leak, not an official release, and Valve has not commented in the sources we checked.

Quick summary

Leakers combined assets from August's 12TB leak with source code and map data that reportedly reached the Valve Cut Content Discord this week.
Videos of the full campaign run under an hour.
Valve has not released or announced F-Stop; it remains canceled.

What is Portal: F-Stop?

F-Stop is a prototype built around a camera. Instead of a portal gun, you photograph an object and place it elsewhere using the resulting Polaroid-style photo. The Verge compares it to the indie puzzler Viewfinder. Some dialogue and ideas later reached Portal 2.

How did the playable version leak?

Most assets came from the 12-terabyte leak that surfaced in August. That dump lacked source code and map data, which The Verge says apparently appeared on the Valve Cut Content Discord this week, letting leakers rebuild a nearly complete game.

Why was F-Stop made?

It came from Valve's Directed Design Experiments, a three-month period in 2007 when the company split into five teams to build new game experiments. That explains why the game is short.

Can you play F-Stop legally?

No official version exists. Distribution of leaked builds is unauthorised, and we are not linking any. Official Portal games are on Steam; for deals, see our free games and deals page.

Does this change anything for Portal fans?

It preserves a piece of game history and shows an alternate path for the series. Nothing suggests Valve will revive it, so treat it as a curiosity. For other leak coverage, see our hardware reports and the launch calendar for confirmed releases.