.f3d

What is a .f3d file?

Autodesk Fusion 360's native format — parametric CAD/CAM in the cloud.

Safe format
Type Cad
By Autodesk
MIME application/octet-stream

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What is it

F3D is the native file format for Autodesk Fusion 360, a cloud-connected parametric 3D CAD/CAM/CAE tool that has become the go-to for makers, startups, and small engineering teams. The format stores the complete design history — every sketch, extrusion, fillet, and boolean operation — so you can go back and modify any step.

The file is actually a compressed archive containing a JSON manifest and binary data for geometry, sketches, timeline operations, rendering materials, and manufacturing setups (CAM toolpaths). Fusion 360's cloud-first architecture means F3D files are typically stored in Autodesk's cloud and versioned automatically, though you can export local .f3d archives for backup or sharing.

Fusion 360 occupies the sweet spot between hobbyist tools (like Tinkercad) and industrial CAD (like SolidWorks or NX). It handles parametric modelling, freeform sculpting, simulation, rendering, and CNC/3D printing toolpath generation in one application. The F3D format captures all of this — which means it's only fully usable in Fusion 360 itself.

Technical details
Full Name
Fusion 360 Design
MIME Type
application/octet-stream
Developer
Autodesk
Magic Bytes
50 4B 03 04 (ZIP)
Safety
.f3d is a known, safe format.
What opens it
Fusion 360
Subscription (free for personal use) Win / Mac
Autodesk Viewer
FREE Web
FAQ
Can I open F3D files without Fusion 360?
Viewing only — Autodesk's free online viewer can display F3D files. For full editing, you need Fusion 360. You can export to STEP or STL for use in other CAD tools.
Is Fusion 360 free?
There's a free personal-use license with some limitations (fewer export formats, no simulation). The full version requires a subscription.
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