OBJ to STL converter

How to convert an OBJ file to STL

Choose the OBJ, keep STL selected as the output format and convert. Polygon faces are triangulated and supported object transforms are applied. Inspect the model from several angles, check that every required piece is visible and download the result.

To convert .obj to .stl reliably, start with an actual surface mesh. This .obj to STL converter needs vertices and faces: renaming a file does not change its format, and isolated vertices or a texture image alone do not describe a printable surface.

Prepare OBJ geometry for a dependable STL export

What changes when you turn OBJ into STL?

The converter retains numeric source coordinates. OBJ does not provide a universally dependable physical-unit declaration, so record a reference dimension and verify it in the receiving slicer. A model drawn as 25 units wide still needs the intended interpretation of those units.

MTL references, colors, textures and UV coordinates do not survive the STL export. A painted logo will not become embossed geometry. If a feature must affect the printed surface, model it as geometry before conversion.

Check the mesh after you change OBJ to STL

A successful file export does not prove the mesh is watertight. Holes, reversed faces, overlapping shells and thin walls may already exist in the OBJ. Review the saved STL in a viewer and then inspect the actual layer paths in your slicer.

This OBJ to STL file converter does not automatically repair holes or perform Boolean unions. If the destination needs one closed solid, make and validate that change in a mesh editor before exporting again.

Review the STL preview · Understand mesh edits and their limits

Can I choose 3MF instead?

The same tool can act as an OBJ to 3MF converter for a geometry handoff: select 3MF in the output-format control. That packages the converted mesh in a different format; it does not preserve the original OBJ materials or recreate a slicer project. Verify dimensions and component placement in the receiving application.

Convert OBJ to STL online without installing software

The web tool runs on your device after loading. No separate OBJ to STL converter software or installer is required. Input is limited to 50 MB, processing to 90 seconds and output to 1.2 million triangles. Simplify a very dense source mesh if it exceeds those limits.

Processing limits

STEP input: 20 MB. STL, OBJ and 3MF input: 50 MB. Output is limited to 1.2 million triangles. Complex models may need simplification in the source application.

One file at a time. Processing stops after 90 seconds. Files remain in browser memory, and no conversion upload is performed. Replacing a file clears the previous result. Closing the tab releases its working data.