Updated June 2026 · runs 100% in your browser
3MF to STL
Convert 3MF models to STL on your device. No upload, no sign-up, no limits.
Drop 3MF files here
or click to choose
🔒 Processed on your device · 0 bytes uploaded
Loads the 3D engine (~1 MB) on first use — cached after that.
How it works
Drop 3MF files and download STL models.
It all runs in your browser with a local copy of three.js — your model never leaves your device, and it stays free, unlimited and private.
About 3MF to STL
3MF is a modern 3D-printing format; STL is the most widely supported. This converts the mesh for any slicer.
Frequently asked questions
How do I use 3MF to STL?
Drop 3MF files and download STL models.
Is my file uploaded?
No. It is converted on your device with a local copy of three.js; nothing is uploaded.
What is a 3MF file?
3MF (3D Manufacturing Format) is a modern 3D-printing format that improves on STL by storing color, materials, and multiple objects together in one compressed file.
What is an STL file?
STL is the standard 3D-printing format. It describes a model's surface as a mesh of triangles but stores no color or texture, which is why it's used mainly for printing rather than rendering.