What are connector pins and how do they work?

STL Splitter automatically generates interlocking connector pins on every cut surface so your pieces align perfectly during assembly. Choose between circular or pentagonal pin shapes, and adjust the tolerance for a tight press-fit or loose slip-fit. Most splitters leave you with flat cuts — connector pins eliminate guesswork when gluing pieces together.

What file formats are supported?

STL Splitter supports STL (binary and ASCII), 3MF, and OBJ file formats. These are the most common formats used in 3D printing and modeling.

Absolutely. All processing happens entirely in your browser. Your files are never uploaded to any server. Your models stay on your device.

How does the cutting work?

The cutting engine uses axis-aligned plane cutting with the Sutherland-Hodgman algorithm. Each triangle that intersects a cut plane is split into smaller triangles, and cap surfaces are generated to create watertight pieces.

Can I print the cut pieces directly?

Yes! Each piece is exported as a valid STL file that can be loaded directly into your slicer software. The pieces include cap surfaces on cut faces for clean prints.

Is there a file size limit?

The maximum file size is 200MB. Processing time depends on the complexity of your model and the number of cuts. Most models process in under a few seconds.

Is STL Splitter free?

Yes, STL Splitter is completely free to use with no limits on the number of files you can process.

STL Splitter — Free Online 3D Model Splitter with Auto Connector Pins

Split large STL, 3MF, and OBJ files into printable pieces and automatically add interlocking connector pins for perfect assembly. The only free splitter with built-in connector pins. Runs in your browser — your files never leave your device.

Key Features

Automatic Connector Pins — Interlocking circular or pentagonal pins are auto-generated on every cut surface for perfect piece alignment. Adjustable tolerance for tight press-fit or loose slip-fit. No other free splitter offers this.
Free & Private — No data leaves your browser. All processing happens locally on your device.
Browser-Based — No downloads or installations needed. Works on any modern browser.
44+ Printer Presets — One-click setup for popular printers from Creality, Prusa, Bambu Lab, and more.
Professional Results — Precise cuts with watertight cap generation for clean, printable pieces.

How It Works

Upload Your Model — Drag and drop your STL, 3MF, or OBJ file (up to 200MB).
Set Cuts — Choose your printer or set custom bed dimensions. Add manual cuts or use auto-split.
Enable Connector Pins — Toggle on connector pins to automatically add interlocking alignment pins to every cut surface.
Download Pieces — Download individual pieces or grab them all as a ZIP file.

Perfect For

Cosplay Props — Split helmets, armor, and oversized props to fit your printer bed.
Home Decor — Print large vases, sculptures, and decorative pieces in sections.
Gaming & Miniatures — Split terrain, buildings, and large-scale gaming accessories.
Engineering — Prototype large mechanical parts and architectural models.

Supported File Formats

STL (binary and ASCII), 3MF, and OBJ — the most common formats used in 3D printing and modeling.