Mesh convert
Upload an STL file and download it as a Wavefront OBJ.
Everything runs in your browser — your files are never uploaded. STEP/IGES use the OpenCASCADE engine (a one-time ~7 MB download) and are tessellated into a mesh, so the result is a surface model, not editable CAD history.
An STL to OBJ converter is a file format translator that takes STL (Stereolithography) 3D models—the standard for 3D printing and CAD—and converts them to OBJ (Wavefront) format, which is widely supported by 3D modeling software, game engines, and visualization tools. Both formats store 3D geometry as polygonal meshes, but OBJ includes better support for materials, textures, and is more universal across creative software.
The converter reads the binary or ASCII STL file, extracts the vertex coordinates and triangular face data, and re-encodes them as OBJ geometry. OBJ format is fundamentally simpler and more human-readable, allowing the tool to also generate an accompanying MTL (material) file if needed. The conversion preserves all mesh geometry—no vertices are lost or altered, only reformatted into OBJ's text-based structure.
| Input | Result | Notes |
|---|---|---|
| dental_crown.stl (2.4 MB, 45,000 triangles) | dental_crown.obj (3.1 MB) + dental_crown.mtl | 3D printing file converted for CAD import; size increases because OBJ is text-based |
| character_model.stl (binary, 100,000 faces) | character_model.obj ready for Blender/Unity | Game asset conversion; OBJ preserves all geometry for seamless import |
| prototype_bracket.stl (1.2 MB) | prototype_bracket.obj compatible with Fusion 360 | Engineering handoff; OBJ format expands collaboration across CAD tools |
No. The converter preserves every vertex and face. Only the file format changes—the 3D geometry is identical. OBJ may appear slightly larger because it uses text encoding instead of binary compression.
The converter auto-detects binary and ASCII STL files. Both types are fully supported; you don't need to do anything different.
Yes, most 3D printing software (Cura, PrusaSlicer, Formlabs) accepts OBJ as readily as STL. OBJ is less common in printing, but fully compatible.
If your model has colors or materials, yes—the MTL file defines those. If your STL is a single color/material, you can import the OBJ alone.
OBJ is text-based and stores coordinates with decimal precision, while binary STL uses compact binary encoding. A 1 MB binary STL typically becomes 2–3 MB as OBJ; this is normal and doesn't affect quality.
OBJ is universal: Blender, Maya, 3DS Max, Fusion 360, SolidWorks, ZBrush, Meshmixer, Cura, PrusaSlicer, Unity, Unreal Engine, and hundreds of free or commercial tools.