Factorio 2.1 is now stable after a long summer on the experimental branch

Wube Software marked Factorio 2.1 as stable on 23 October, exactly two years after Space Age launched. The update spent the summer on the experimental branch, and Friday Facts #449 says many of the tweaks since the first 2.1 build came straight from player bug reports.

Don’t expect new planets, enemies or research trees. Wube describes 2.1 as a large collection of quality of life changes, small features and polish, the things it wanted for 2.0 but ran out of time for. If you stayed on stable 2.0, all of it lands at once.

Space platforms get the most attention. Rockets can now carry several different items in one launch, so building a small platform no longer means shipping a full stack of everything. Leave the “Import from” slot empty and a platform pulls from every location, which suits fuel, ammo and repair packs. Platforms can also trade items with each other in orbit, and the circuit network can now drive hub requests. A new Radar Universe mode passes signals between planets and platforms on a shared channel.

Flight physics changed too. Asteroid damage now depends on the asteroid’s remaining health rather than its speed, and drag is based on mass instead of width. The pencil ship is no longer the only fast ship.

Other highlights from the announcement:

• A landing pad unloading bay that inserters can empty straight into trains, belts or chests
• Circuit reads and writes can go to different wire colours, labs can pick research from signals, and pipes and boilers join the network
• Space Age can be played without Quality, with the Recycler split into its own mod
• Quality modules no longer work in asteroid reprocessing, closing the “space casino”
• Pipes carrying different fluids refuse to merge and show a warning instead
• Biter expansion groups now scale with evolution and pick more natural spots

For anyone running a server, two points stand out. Factorio now runs natively on ARM64 Linux, and Wube specifically mentions headless servers on a Raspberry Pi. More important is the warning about saves: 2.0 games load, but changes such as the circuit input/output split can break existing builds. After updating, saves and blueprints cannot be downgraded to 2.0, so Wube recommends backing up anything you care about first.

Most popular mods were updated during the experimental period, though some may still be missing. If your server runs mods, check that each one has a 2.1 release before you switch the server over.