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.brepBREP→.3mf3MFtessellated

Convert BREP to 3MF

Convert BREP to 3MF in your browser. The conversion runs on this page and the file never leaves your computer.

Drop your .brep file

up to 250 MB · .brep .brp

Free, and it opens in this tab. Nothing is uploaded, and there's no account to make.

Runs locally · nothing uploaded · the CAD kernel loads once you choose a file

Before you convert: what this keeps and what it destroys

Preserved

  • The shape, to within the tessellation tolerance
  • Overall dimensions and proportions
  • Watertightness, where the input is watertight
  • The unit, recorded in the file

Destroyed

  • Exact curves and surfaces, replaced by triangles
  • The feature tree and any parametric history

about .brep · about .3mf · just view it instead

Why people convert BREP to 3MF

Choose this one if the part is going to a printer. It fixes the single real weakness a .brep has.

A .brep records no unit at all. Its numbers are read as millimetres by Open CASCADE convention and by this site, but nothing in the file says so, and that assumption travels silently into every format that also stores no unit. 3MF breaks the chain: it writes millimeter into the file explicitly, so from here on nobody downstream has to assume anything.

You also get a smaller file than the STL equivalent and, where the BREP held several solids in a compound, they arrive as separate objects on the build plate rather than one merged body.

What you get

You get a binary 3MF file containing triangles. The reader tessellates supported surfaces or uses saved render meshes where required by the source format. Inspect curved faces at the intended output size. The triangle count depends on the model and the reader's meshing settings.

Carried across: the unit, recorded in the file.

The conversion runs in your browser. Your file stays on your computer and is not uploaded.

What to check afterwards

  • BREP carries no unit. The numbers in the file are just numbers, so the conversion assumes millimetres. Check the overall dimensions of the result before you commit to machining or printing it. A file exported from a package set to inches will be 25.4 times out.
  • Curves become facets. BREP stores exact surfaces, so a hole is a cylinder with a radius. 3MF stores triangles, so that cylinder becomes a many-sided prism. Look at curved faces in the result at the size you intend to make the part.

If you need something this conversion cannot give you

If you need editable CAD geometry, don't convert at all. Open the BREP file directly in FreeCAD, Fusion, Onshape or SolidWorks. Every mesh format destroys the exact surfaces, and no later conversion brings them back.

Going the other way

This site reads BREP but does not write it. For the reverse conversion, use an application that can export BREP.

How we know this conversion works

This pair was checked against 1 file from the test corpus on 2026-09-04. Each run parses its own output back in and compares the bounding box, the triangle count and, for closed solids, the volume against the input.

A pair that fails those checks doesn't get a page. That's why this site lists 120 conversions and not the several hundred a format-times-format grid would suggest.