Free Online 3D Format Converter

Convert 3D models between OBJ, STL, and GLB formats. All processing happens in your browser using WebAssembly — your files never leave your device. No upload, no signup, completely free.

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Why Polyvia3D?

100% Private

Your files never leave your device. All conversion happens locally in your browser using WebAssembly. No server upload, no data collection.

Lightning Fast

WebAssembly-powered conversion runs at near-native speed. Typical models convert in seconds. Supports files up to 50MB on desktop.

Completely Free

No hidden costs, no watermarks, no account required. Convert unlimited files. Works on any modern browser.

Supported Conversions

Convert between OBJ, STL, and GLB formats. Click any conversion to get started.

OBJ to STLOBJ to GLBSTL to OBJSTL to GLBGLB to OBJGLB to STL

Perfect For Every 3D Workflow

3D Printing

Convert OBJ or GLB models to STL for slicing in Cura, PrusaSlicer, or Simplify3D. Perfect for the Blender-to-printer workflow.

OBJ to STL →

Web3D & AR/VR

Convert OBJ or STL models to GLB for Three.js, Babylon.js, WebXR, or Google model-viewer. Display interactive 3D on any website.

OBJ to GLB →

DCC Editing

Convert STL or GLB to OBJ for editing in Blender, Maya, 3ds Max, or other digital content creation tools. Add materials, sculpt, and refine.

STL to OBJ →

Frequently Asked Questions

Polyvia3D supports three major 3D formats with 6 conversion directions: OBJ to/from STL (for 3D printing workflows), OBJ to/from GLB (for Web3D/modeling interchange), STL to/from GLB (for web visualization of 3D prints). More formats (FBX, USDZ, GLTF) are planned for future releases.
Yes, completely free with generous file size limits: Desktop up to 50MB per file, Mobile up to 25MB per file (with warnings for files 10-25MB). No hidden costs, no watermarks, no account required.
No. All conversions happen locally in your browser using WebAssembly (WASM) technology. Your files never leave your device. We don't receive, store, or transmit any user files. This is the core privacy advantage of Polyvia3D.
Yes. You retain all intellectual property rights to your files. Polyvia3D does not claim any ownership. However, ensure you have the right to use the source files (e.g., respect Creative Commons licenses on downloaded models).
No. Polyvia3D works entirely in your web browser. No downloads, no plugins, no account registration. Just visit the page and start converting.
Polyvia3D works on any modern browser that supports WebAssembly: Chrome 111+ (recommended), Firefox 128+, Safari 16.4+, Edge 111+. Internet Explorer is not supported.
Partially. Once the page and the conversion engine (WASM module) are cached, you can convert files without an internet connection. However, the initial page load requires internet access.
Geometry (vertices, faces) is preserved accurately in all conversions. However, some data may be lost depending on the format pair: converting to STL discards materials and textures, converting to STL or GLB may triangulate polygon faces, converting from GLB to OBJ/STL discards animations and scene hierarchy. See individual tool pages for details.