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Your STL is converted on your own computer and never uploaded. Files up to 300 MB are accepted.
STL to OBJ Converter
Turn STL files into OBJ for Blender, game engines and 3D apps. Binary or ASCII, batch-ready, nothing uploaded.
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Converted in your browser. Files are never uploaded.
Continue with your OBJ
Check the converted file, or turn the same STL into another format.
How to convert STL to OBJ
- 1
Add STL files
Drop binary or ASCII STLs, one at a time or a whole batch.
- 2
Check the model
Rotate it on the plate, confirm the size, and resize the longest side if you need a different scale.
- 3
Download the OBJ
Save an OBJ turned Y-up, so it stands upright when Blender or a game engine imports it.
Why use this STL to OBJ converter
Made for print files that need to move into a modeling app or game engine.
One connected mesh
Corners shared by neighboring triangles are welded, so each object imports as one editable mesh instead of thousands of loose faces.
Size shown before you export
Each STL sits on a build plate with its dimensions in millimeters or inches and its triangle count.
Whole folders in one go
Drop many STLs at once and download one OBJ per file, packed together in a single ZIP.
What changes when STL becomes OBJ
Both formats store triangles, so nothing about the shape is lost. The OBJ is simply easier for 3D apps to edit.
Kept
- Every triangle of the mesh
- The size in millimeters, as one OBJ unit each
- Up direction, turned from Z-up to Y-up
- Smooth vertex normals for cleaner shading
Left behind
- STL color extensions some tools write
- Materials and textures, which STL never had
- UV coordinates for texturing
- Nothing else: the shape converts one to one
STL to OBJ questions
Answers about scale in Blender, ASCII files, batches and cost.
Why convert STL to OBJ?
OBJ is the more common exchange format in Blender, Maya, Unity and Unreal, and it shares vertices between faces, which makes meshes easier to edit and texture.
My OBJ is huge in Blender. Why?
STL sizes are millimeters, and Blender reads OBJ units as meters, so 100 mm becomes 100 m. Set the import scale to 0.001, or turn on Resize longest side before converting.
Can I convert ASCII STL files?
Yes. Both binary and ASCII STL are detected automatically.
Can I convert many STLs at once?
Yes. Drop them all in and you get a ZIP with one OBJ per STL.
Is the STL to OBJ converter free?
Yes. No sign-up, no limit, and files never leave your browser.