A mod (short for modification) is an alteration of the game. Modifications can range from small tweaks to total conversions.
Starting in Factorio version 0.13, mods are available from within the game via the Mods option on the main menu. Here you'll find all mods published to the official Factorio mod database. If you want more information on a mod, visit its page at mods.factorio.com.
Other mod listings exist as well, most importantly factoriomods.net and the forums. Although mods you find there must be manually installed, that's pretty easy—see "Manual installation" below for how.
Installing a downloaded mod is very easy:
- Find mod you like. It must support the version of Factorio that you have installed.
- Download the mod. This will normally come as a ZIP file. Do not unzip it.
- Copy the ZIP into the appropriate directory. For Windows that's
%appdata%\Factorio\mods, for Mac it's
~/Library/Application Support/factorio/mods/, and for Linux it's
~/.factorio/mods. If the directory doesn't exist, create it.
- Launch Factorio. New mods are enabled by default, so you can start using the mod immediately.
Xterminator has made a video tutorial for that (Windows only).
Gotchas about using mods
- Some mods only work properly with maps created after the mod is installed. Typically the mod description will warn you about that.
- If you install a mod that prevents Factorio from launching, you can simply delete the mod from the mods folder. See "Manual installation" for the location.
- Note: You may want to check whether there's already a newer version of the mod that fixes the problem. Even high-quality mods can break as Factorio changes.
- Some mods require other mods as dependencies. Factorio does not automatically pull in dependencies. The mod description will normally tell you if there are any.