A single-file browser tool that separates multi-object STL files into individual objects for selective export.
STL files often contain multiple disconnected 3D objects packed into a single file. STL Splitter automatically detects and separates these objects using vertex connectivity analysis (Union-Find), displays them with distinct colors in a 3D viewport, and lets you export selected objects as individual STL files.
- No server, no installation — just open the HTML file in a browser.
- Start STL-Splitter
- Demo to start by passing stl file URL
Open a file — Drag & drop an STL file onto the page, or click to browse. Both binary and ASCII STL formats are supported.
Load via URL parameter — Append ?file= to auto-load an STL from a URL path:
stl-splitter.html?file=./models/part.stl
stl-splitter.html?file=https://example.com/model.stl
Select objects — Click items in the sidebar to toggle selection. Deselected objects become translucent in the viewport.
Export — Choose either:
- Merge export — Save all selected objects as a single STL file.
- Separate export — Download each selected object as its own STL file.
Viewport controls:
- Left drag: Rotate
- Shift + drag / Middle drag: Pan
- Scroll: Zoom
| Item | Detail |
|---|---|
| Format | Single HTML file (HTML + CSS + JS) |
| Dependency | Three.js r128 (loaded from CDN) |
| STL input | Binary and ASCII |
| STL output | Binary |
| Separation method | Union-Find on spatial-hashed vertices |
| Tolerance | Configurable vertex merge distance (default 0.001) |
| URL parameter | ?file=<path-or-url> — fetch and load on startup |
| Browser support | Modern browsers (Chrome, Firefox, Edge, Safari) |