Convert between STL, OBJ, PLY, glTF and CAD formats (STEP, IGES) — entirely in your browser.
Input file
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.
Share
What is the 3D Model Converter?
A 3D model converter is software that translates 3D geometry files from one file format to another. Each format—STEP, STL, OBJ, IGES, etc.—encodes 3D shape data differently: some store surfaces and solids (STEP, IGES), others store triangulated mesh data (STL, OBJ), and others compress geometry for real-time rendering (GLTF, 3MF). The converter reads one format and writes another, making models portable across CAD, 3D printing, animation, and game-design tools.
How it works
Upload your 3D file in any supported source format. The converter parses the file's geometry definition, applies format-specific transformation rules (e.g., converting parametric surfaces to mesh triangles or vice versa), and outputs the result in your chosen target format. The conversion respects coordinate systems, units, colors, and texture information where applicable, ensuring your model's structure and proportions survive the translation.
Examples
Input
Result
Notes
STEP file (CAD assembly with solid features and parametric edges)
STL file (triangulated mesh ready for 3D printing slicing software)
STEP → STL is the most common conversion for additive manufacturing; triangle density determines print detail
OBJ file (textured polygon mesh from 3D scanning or photogrammetry)
GLTF file (optimized, compressed geometry for web and real-time viewers)
IGES file (legacy mechanical design with surfaces and wireframe geometry)
STEP file (modern, feature-based solid model format)
IGES → STEP preserves design intent and allows further CAD editing
How to use the 3D Model Converter
Click or drag your 3D model file into the upload area
Select the target format (STL, OBJ, GLTF, STEP, IGES, PLY, 3MF, etc.)
If needed, configure output options (mesh density, scale, unit conversion, decimation)
Click Convert and wait for processing to complete
Download the converted file to your computer
Open the result in your CAD, 3D print, or visualization software
Benefits
Eliminate format compatibility walls—use any model in any software without re-creating geometry from scratch
Reduce file size when converting mesh formats (e.g., OBJ to GLTF), saving storage and speeding uploads
Prepare CAD designs for 3D printing by converting STEP or IGES to printable STL meshes
Enable real-time rendering by converting static CAD files to lightweight web formats (GLTF, 3MF)
Preserve model accuracy during translation, avoiding visual artifacts or loss of fine detail
Work offline after download—no ongoing subscriptions or cloud dependencies
Tips & common mistakes
Common mistakes
Assuming all formats preserve color and texture—OBJ and STL require separate MTL/PNG files for appearance; GLTF embeds textures natively
Converting STEP → STL with default mesh settings, resulting in coarse triangulation that loses sharp edges (adjust triangle density beforehand)
Forgetting to confirm unit consistency—a model created in millimetres but imported as inches becomes 25× smaller; check source metadata
Tips
For 3D printing, always convert to ASCII or binary STL; validate the mesh in a slicer tool (Cura, PrusaSlicer) before printing to catch topology errors
When sharing geometry with collaborators using different CAD software, STEP is the most universally supported neutral format
If importing GLTF into a game engine (Unreal, Unity), pre-convert colours/textures to PNG and re-link them in-engine for best quality
Large assemblies (500+ parts) convert faster and cleaner if exported as single solids rather than preserved hierarchies
Frequently asked questions
Will converting a STEP file to STL lose any detail?
Not if you set mesh resolution high enough. STEP stores continuous surfaces; STL approximates them with triangles. Finer triangle density = closer match, but larger file size. For precision work, keep triangle edge length ≤0.1 mm of your smallest feature.
Can I convert an OBJ file back to STEP and edit it in CAD software?
No—OBJ is a mesh format (just triangles); STEP is a solid/feature format. You can convert OBJ → STEP technically, but the result is a mesh shell with no parametric features. You'll need to rebuild edges and constraints in CAD by hand if you want true editability.
What's the file size limit?
Most online converters support 100 MB–1 GB depending on server capacity. For massive assemblies, split them into subassemblies, convert individually, and re-combine in your destination software.
Do I need to install any software to use this converter?
No. This is a web-based tool—just upload and download. No plugins, no CAD licenses, no Python scripts needed.
Which format is best for 3D printing?
STL (Stereolithography) is the industry standard. It's simple (just triangles), lightweight, and directly readable by all slicing software. For high-speed 3D printing, 3MF is newer and includes color and support hints.
Can the converter handle assemblies with multiple parts?
Yes. If converting a STEP assembly to STL, you can merge all parts into one STL or export each component separately. Check the output options during conversion.