F3D — The Complete Guide: A Fast, Minimalist 3D Viewer for Free
F3D is an open-source 3D file viewer (BSD-3-Clause) that opens quickly and does one thing — it displays. It suits an engineer who wants to see what is inside a STEP or STL file without waiting for a full CAD program to load.
F3D
F3D-APP Foundation
Fast, minimalist 3D viewer — STEP, STL, OBJ, glTF and PLY, including thumbnails in the file manager.
Get it from the vendorWhat you get
- CAD models — opens STEP files.
- Meshes — STL, OBJ and PLY.
- Modern formats — glTF and USD.
- Scientific and volume data — shown with realistic lighting and materials.
- Thumbnails — on Windows and Linux you see the model in the file manager without opening it.
When it is enough
F3D is a viewer only: there is no editing and no advanced measurement. It is excellent for reviewing a folder full of parts, checking a file before printing or sending it, and quick viewing on Windows, Linux and macOS. When you need to measure, repair a mesh or edit, move to another tool.
Related tools
For viewing in the browser with no installation — Online 3D Viewer. For processing and repairing meshes — MeshLab. For viewing CAD files and converting between formats — Mayo.
Online 3D Viewer
Online 3D Viewer project
Open STEP, IGES, IFC, STL, OBJ and more in the browser — files are processed locally, not uploaded to a server.
Get it from the vendor
MeshLab
ISTI — CNR
Mesh and point cloud processing — hole filling, simplification, alignment and format conversion.
Get it from the vendor
Mayo
Fougue
3D CAD viewer and converter — STEP, IGES, BREP, STL, glTF and OBJ — with measuring tools and clip planes.
Get it from the vendor
FreeCAD
FreeCAD Project
Open-source parametric 3D modeller with workbenches for solid modelling, FEM, drafting and BIM.
Get it from the vendorThe bottom line
F3D is a free viewer that every mechanical engineer should have installed — small, fast and open.