LeoCAD
FreeBuild LEGO models on screen, then export the parts list and go buy the bricks
Open-source virtual brick building software based on the LDraw standard, with more than 10,000 parts included. Build in steps and submodels to produce building instructions, import LEGO Digital Designer LXF files and official set inventories, and export BrickLink wanted lists, CSV, POV-Ray, OBJ and other formats.
Why we picked it
GPL-2.0, 2,874 stars. Version 26.09 was released on 20 September 2026 after 25.09 a year earlier, and commits keep coming in between.
Anyone designing their own LEGO models (MOCs) runs into a practical problem: you rarely own the right bricks. You build it on screen first, settle the structure and colors, then buy parts from a list. LeoCAD covers that stage. Its library follows the LDraw standard with more than 10,000 parts and works with LDraw tools such as LDView and LPub3D, so the large body of LDraw models online opens directly.
A few practical features:
- Import parts by set. Pick an official set number and all its parts are added, handy when modifying a set you already own.
- BrickLink export. Export an XML parts list and upload it to BrickLink as a wanted list.
- Steps and submodels. Record which bricks go in at each step to produce building instructions, and split large builds into submodels.
- LDD import. LXF files from LEGO Digital Designer, which LEGO discontinued, can be read in.
To be clear about:
- It is not official LEGO software. BrickLink Studio is also free and stronger at rendering and part price lookups, but it is closed source. LeoCAD wins on being open, lightweight and offline.
- Parts from new sets have to be modeled by the LDraw community first, so the newest pieces may be missing for a while.
- The interface and viewport rendering are plain. For showcase images people usually export to POV-Ray or Blender and render there.