Free 3MF Editor — Edit & Convert 3MF Files Online

Edit 3MF files online, free and in your browser. Open a 3MF, resize to exact millimetres, combine and hollow it, repair the mesh, and export 3MF, STL, OBJ, or GLB. No install, no sign-up to start.

Edit 3MF files online, true to size.

Open a 3MF, resize it to exact millimetres, combine and hollow it, repair it for printing, and export 3MF, STL, OBJ, or GLB — free, in your browser, no install.

Free to use · Runs in your browser · Start without an account

A real editor for the modern print format

3MF keeps units and scale where STL doesn’t — and OwlCAD is built around true millimetres, so it’s a natural fit.

Open & convert 3MF

Drag a .3mf onto the build plate — or import an STL and export 3MF. OwlCAD reads and writes both, plus OBJ and GLB, with units detected on the way in.

True-to-size editing

3MF carries real-world units, and OwlCAD works in true millimetres, so parts keep their intended size. Move, rotate, and scale to exact values.

Combine & cut

Boolean union, subtract, and intersect your 3MF against parametric shapes — merge parts, add tabs, or cut holes, non-destructively.

Hollow & repair

Shell a model to a set wall thickness, add drainage holes, and run the print check to repair non-watertight geometry before your slicer sees it.

Drop in a 3MF and start editing

No download, no account needed — your work saves in the browser as you go.

Frequently asked questions

Is the OwlCAD 3MF editor free?

Yes. Open, edit, and export 3MF files free in your browser — no install, no sign-up to start. Only AI generation is part of the paid Pro plan.

How do I edit a 3MF file online?

Drag a .3mf onto the build plate, then move, rotate, and scale to exact dimensions, combine it with parametric shapes using booleans, hollow it into a shell, or repair the mesh — then export 3MF again.

Does 3MF keep the right size and scale?

Yes. 3MF carries real-world units, and OwlCAD works in true millimetres throughout, so a part keeps its intended size on import and on export — ideal for 3D printing.

Can I convert 3MF to STL, or STL to 3MF?

Yes — import either and export the other (plus OBJ and GLB). 3MF is the more modern, slicer-friendly format; OwlCAD reads and writes both.

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