Convert OBJ
to STL.

Updated 2026-10-19

To convert OBJ (.obj) to STL (.stl), drop the file below and download the result, in the browser with nothing installed. A direct mesh conversion: the triangles are rewritten, not rebuilt.

5 conversions a day with no account. No card, no install. In your browser: no daily limit, and the file is never uploaded.

No account needed
Drop a OBJ file.obj · up to 200 MB

On our servers. No account: deleted within 24 hours. Signed in: kept until you delete them. Never shared or used for training.

ResultMesh

The shape is unchanged — same triangles, same dimensions. Only the container changes.

HowThree steps
  1. Drop your .obj file above — up to 200 MB without an account.
  2. STL is already selected as the output.
  3. Download the .stl. Without an account, files are deleted within 24 hours; signed in, they are kept until you delete them.
FormatsWhat you are holding

Wavefront OBJ file (.obj)

OBJ is a plain-text mesh format from graphics. Unlike STL it keeps named groups, texture coordinates, materials and polygon faces, which makes it the usual handover into rendering and texturing tools. It is still a mesh, not a solid.

The destination is a renderer, game engine, texturing tool or visualisation pipeline.

STL file (stereolithography) (.stl)

STL is the lingua franca of 3D printing: a flat list of triangles. No unit, colour, material or history — a cylinder is a fan of flat strips. The missing unit is the classic cause of scale accidents. Every slicer and mesh tool reads it.

You are printing, meshing or sending to a bureau — where triangles are what is wanted.

Questions6 answered
Is the OBJ to STL converter free?
Yes. 5 conversions a day with no account and no card. A free account raises the limit and adds 25 credits. Choose In your browser instead and there is no daily limit at all.
Does anything change in the geometry?
A direct mesh conversion: the triangles are rewritten, not rebuilt. The shape is unchanged — same triangles, same dimensions. Only the container changes.
Will the STL file be the right size?
It is written in millimetres. STL records no unit, so choose millimetres if your slicer asks. 3MF records units in the file.
How big a file can I convert?
To a mesh format like STL: 300 MB with a free account, 200 MB without one. To STEP, Parasolid or SLDPRT: 140 MB, because rebuilding a solid takes about twice the memory of writing a mesh. Maker and Studio convert up to 830 MB and 380 MB — a large conversion on a paid plan gets the server to itself.
Is it safe to upload my OBJ file?
Files travel encrypted and are processed by machine on our own servers — no third parties, no ads or trackers, no AI training. Or skip the upload: choose In your browser above the drop zone and this conversion runs on your own device, so the file never leaves it.
Is my OBJ file deleted after converting?
Without an account, the upload and the result are deleted within 24 hours. With an account, both stay in your files until you delete them; deleted files leave our servers within 24 hours.
Beyond convertingSame file, four workspaces

Keep the part open: fill it with a lattice, check it with FEA, texture a surface, or slice it into cut-ready sheets. These workspaces are in early access — create an account, then apply from inside the app.

Create free account See pricing

AlsoOther ways in
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Going the other way? Convert STL to OBJ.