Convert STL to OBJ
Convert STL to OBJ free in your browser. No upload, no signup, no watermark. Files stay on your device.
drop a .stl file
or click to browse
related
more stl & obj
see all 3D model converters →guide
how to convert stl to obj
Drop your STL file
Drag your STL file into the drop zone above, or click the box to pick a file from your computer or phone. The browser reads the file directly — nothing uploads.
Click Convert
The page runs three.js on your device to decode the Stereolithography and encode it as Wavefront OBJ. Most conversions finish in a few seconds; large or codec-heavy files (RAW, video) can take longer.
Download the OBJ file
When the conversion finishes, the OBJ file is ready to download. Save it anywhere on your device.
FAQ
common questions
Why convert STL to OBJ?
STL is great for 3D printing but limited — it stores only triangles, no materials or colours. OBJ adds material support via a sidecar MTL file, plus it preserves vertex groups and is more widely understood by 3D modelling tools. If you're moving a printable model into Blender, Maya, or another 3D app for editing or rendering, OBJ is the more workable format.
Will I gain materials or textures from the conversion?
No — you can't add what wasn't there. STL files don't carry material information; the OBJ output preserves the same geometry without inventing colours or textures. You'd add materials yourself in a 3D editor after conversion. The OBJ container is capable of holding them; the source STL just doesn't have any to transfer.
Will the geometry survive exactly?
Yes — every triangle in the STL becomes a face in the OBJ. The conversion preserves vertex positions and the triangle mesh exactly. OBJ supports more advanced geometry (quads, n-gons, vertex normals, UV coordinates) but the converter doesn't synthesise those from STL data; the output mesh is triangulated like the source.
Will the OBJ be larger than the STL?
Usually somewhat larger because OBJ is text-based (each vertex listed as text coordinates with newlines) while STL is binary (more compact per triangle). A 10 MB STL commonly becomes a 15–25 MB OBJ. Binary OBJ variants exist but most apps expect the text form, which is bigger but more human-inspectable.
Can I still 3D-print the OBJ?
Most slicers accept OBJ alongside STL — Cura, PrusaSlicer, Bambu Studio, and others all import OBJ. So yes, you can slice and print directly from OBJ. STL is still the canonical 3D printing format (every slicer accepts it without question), but OBJ works in modern printing workflows too.