STL to OBJ Converter with Private Interactive 3D Preview
Convert ASCII or binary STL to OBJ directly in your browser. Rotate and inspect the mesh, review triangle count and dimensions, then download a Wavefront OBJ without uploading your model.
STL parsing, 3D preview and OBJ export happen in this browser. Your model is never uploaded.
No STL selected
Load a triangle mesh to inspect it before exporting a standards-compatible Wavefront OBJ file.
How to convert STL to OBJ online
Load an STL mesh, inspect its geometry in the interactive viewer, then export a compatible Wavefront OBJ file.
Choose an STL file
Drop an ASCII or binary .stl model up to 100 MB. The browser validates the mesh and supports up to one million triangles.
Inspect the mesh in 3D
Drag to rotate, scroll to zoom, and review STL encoding, triangle count, vertex count and model bounds before export.
Download the OBJ
Select Convert STL to OBJ to create a text-based Wavefront OBJ containing the mesh coordinates, normals and faces.
STL to OBJ conversion details
The converter reads STL triangle coordinates and facet normals locally, then writes them as OBJ vertices, normals and faces.
| Control | Setting | Effect |
|---|---|---|
| Processing | Local browser | The proprietary or private 3D model never goes to a conversion server |
| STL input | ASCII or binary | Automatically parses both standard STL encodings |
| 3D inspection | Rotate and zoom | Lets you confirm the expected mesh loaded before downloading |
| Geometry limit | 1,000,000 triangles | Keeps high-poly browser conversion within a practical memory budget |
| OBJ output | Vertices, normals and faces | Creates portable Wavefront geometry for editing and interchange |
STL vs OBJ for 3D printing and editing
STL is a compact triangle-surface format used by slicers. OBJ is readable, editable and widely supported by modeling and rendering software.
| Characteristic | Source | Output |
|---|---|---|
| Primary use | 3D printing, CAD export and slicing | Model editing, rendering, games and interchange |
| Geometry | Independent triangle facets | Shared or repeated vertices, normals and polygon faces |
| Encoding | Binary or ASCII | Readable text |
| Materials and textures | Not supported by standard STL | Can reference MTL materials and UV textures |
| Units | No required unit metadata | No required unit metadata; verify scale after import |
What the OBJ export preserves
Format conversion preserves the source mesh shape, but it cannot create materials, textures or scene data that are absent from standard STL.
The mesh shape is preserved
Every readable STL triangle is exported as OBJ vertex and face data. The conversion does not intentionally simplify or resample the surface.
Materials cannot appear from nowhere
Standard STL stores no MTL material, UV coordinate, image texture or scene hierarchy. The generated OBJ therefore contains geometry and normals only.
Check scale and orientation
STL and OBJ are effectively unitless. Confirm millimeters, inches, meters and the expected up-axis when importing into Blender, Maya, Unity or another target app.
Conversion is not mesh repair
Holes, non-manifold edges, self-intersections, duplicate facets and inverted normals can remain. Repair production meshes in Blender, MeshLab or CAD software.
Related 3D model converters
Reverse the conversion for a slicer or move GLB scenes into STL and FBX workflows.
STL to OBJ converter FAQ
How do I convert STL to OBJ?
Choose an STL file above, inspect the model in the 3D preview, select Convert STL to OBJ, then download the generated .obj file.
Is this STL to OBJ converter free?
Yes. You can convert models within the displayed file and triangle limits without payment, registration or software installation.
Is my STL file uploaded?
No. STL parsing, 3D rendering and OBJ generation all happen locally in your browser, so the model never leaves your device.
Does it support binary and ASCII STL files?
Yes. The converter automatically detects and parses both standard binary STL and text-based ASCII STL files.
Does converting STL to OBJ lose quality?
The exporter keeps the readable triangle coordinates without mesh simplification. Floating-point text formatting can change insignificant numeric precision, but the mesh is not intentionally reduced.
Will the OBJ include colors, materials or textures?
No. Standard STL contains only surface triangles and normals, so it provides no material, texture or UV data to include in the OBJ.
Can I use the OBJ in Blender?
Yes. Wavefront OBJ is supported by Blender, Maya, 3ds Max, Cinema 4D, ZBrush, Unity, Unreal Engine and many CAD or mesh tools.
Does the converter repair a broken STL mesh?
No. It changes the file representation without closing holes, making a mesh watertight or fixing non-manifold and self-intersecting geometry.
Why is the OBJ the wrong size after import?
STL and OBJ do not reliably declare real-world units. Set the intended units or scale in the destination application after import.
What is the largest STL I can convert?
The current browser limit is 100 MB and one million triangles. Practical capacity also depends on available device memory and graphics support.
Can I convert STL to OBJ on mobile?
Modern mobile browsers can process smaller models, but desktop browsers are more reliable for large or high-poly STL files because they have more memory and GPU capacity.
Convert and inspect your STL privately
Load the mesh, verify it in 3D, and export OBJ geometry without sending the model to a server.
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