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Convert OBJ to STL, free and online

Drop an .obj export from Blender, ZBrush or CAD, spin it around in 3D, and save an STL every slicer reads. The whole thing runs on your device, so the file is never uploaded.

Drop an OBJ file here

or choose a file — writes a print-ready STL on the spot. Already have an STL? Drop it to preview and re-save it.

.OBJ · .STL · max ~200 MB
drag to rotate · scroll to zoom
File—
Triangles—
Vertices—
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Want it in color? STL holds geometry only, so any texture or vertex color in your OBJ is gone once it's an STL. Paint your model per-region in Layerpaint and export a Standard 3MF your slicer prints in multiple filaments.

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🔒 Files are processed locally in your browser and never uploaded.

OBJ to STL in one drop

OBJ is what Blender, ZBrush and most CAD packages hand you when you export a mesh, and it can carry texture maps, UVs and vertex colors alongside the geometry. Slicers and print services mostly want STL, the plain triangle format every printing tool understands. When something only takes STL, drop your OBJ here and you'll have one in a couple of seconds.

Nothing is uploaded. The .obj text is decoded and parsed in your browser, the mesh appears in the live 3D preview above, and the binary STL is written locally for download. Useful when the model is a client's, a paid sculpt, or anything you'd rather keep off a stranger's server.

What STL drops from your OBJ

STL is geometry and nothing else — no UVs, no texture maps, no vertex colors. An OBJ can reference all of those, and they don't survive the trip to STL. That's fine if you only need the shape for a single-color print. If color is the goal for multi-filament or AMS printing, don't flatten it away: paint the model in Layerpaint and export a Standard 3MF your slicer prints in real filament.

Faces, n-gons and multiple objects

The converter reads every f face line, fan-triangulates n-gons, and merges any groups or sub-objects into one mesh before writing the STL. Materials and UVs are skipped on purpose — this is a geometry converter, so the STL you get is clean triangles ready to slice.

Questions

Why convert OBJ to STL?
OBJ is a common export from Blender, ZBrush and CAD apps, but a lot of slicers and print services want STL. STL is the universal mesh format, so converting gets your model into any slicer or printer that only takes STL.
Does it keep OBJ textures or vertex colors?
No. STL has no textures, no UVs and no vertex colors — it's geometry only. Anything an OBJ references there is dropped. To keep color for multi-filament printing, paint in Layerpaint and export a Standard 3MF.
Will the STL open in my slicer?
Yes. The output is a standard binary STL that loads in Bambu Studio, OrcaSlicer, PrusaSlicer, Cura and any STL viewer. Units pass through unchanged and are treated as millimeters.
Is my OBJ uploaded anywhere?
No. The OBJ is read and converted entirely on your device in JavaScript. Nothing is sent to a server, so large or private models stay with you.
What if my OBJ has multiple objects or groups?
All faces are read into a single mesh and written as one STL. Materials, groups and UVs are ignored — this is a geometry converter, not a material importer. Need the parts kept separate or painted? Open the file in the Layerpaint painter.