Mesh Boolean Tool
LocalBoolean union, subtract or intersect two meshes (STL/OBJ/PLY/3MF/GLB/GLTF) and export STL — watertight manifold results, live preview, no upload. Pro feature.
A (base)
Drag files here, or click to browse
Supports STL, OBJ, PLY, 3MF, GLB, GLTF
Choose fileB (tool)
Drag files here, or click to browse
Supports STL, OBJ, PLY, 3MF, GLB, GLTF
Choose fileMerges A and B into one solid
A and B preview on the page first (B is the amber tool body). After both load, the viewport live-updates the boolean result for the current operation (manifold kernel with BVH fallback, 300ms debounce) — meshes over 200,000 combined faces skip live preview and are computed only by the button. Clicking the button computes and downloads the STL. Files are not uploaded.
The manifold kernel requires oriented manifold input (auto-welded from triangle soup); the BVH fallback accepts looser geometry.
What is it? Mesh Boolean Tool performs union, subtract and intersect operations between two meshes (STL/OBJ/PLY/3MF/GLB/GLTF) and exports the result as binary STL, all locally in your browser. Once A and B are loaded, the viewport live-updates the boolean result (manifold-3d kernel with three-bvh-csg fallback, 300ms debounce); empty results — an intersection that misses, or a union of two non-touching solids — are reported explicitly, never as fake success.
TL;DR: Union, subtract or intersect two meshes and export a watertight STL — live preview, manifold kernel with BVH fallback, runs locally in your browser.
How to use
- Drop mesh A (base) and mesh B (tool) — both preview on the page (B in amber).
- Choose Union, Subtract or Intersect — the boolean result live-updates in the viewport (manifold kernel with BVH fallback, 300ms debounce; meshes over 200,000 combined faces skip live preview and are computed only by the button).
- Click Boolean & download STL to compute and save the result.
FAQ
Do the meshes need to be watertight?
Yes — clean, watertight inputs give the most reliable results; repair first with Mesh Doctor.
Is it local?
Yes, the boolean runs in your browser.
Is it free?
No — Mesh Boolean is a Pro feature; on the Free plan this page shows an upgrade prompt.
What's the difference between union, subtract and intersect?
Union merges both meshes into one solid; subtract (A − B) cuts mesh B out of mesh A; intersect keeps only the overlapping volume. The result is always exported as binary STL.
Is the exported STL watertight?
Yes when the inputs are manifold — the manifold-3d kernel guarantees a watertight result. Non-manifold inputs automatically fall back to the BVH kernel, which does not guarantee watertightness; the page reports which kernel was used and warns (amber) when a result is empty.
How large can my meshes be?
Live preview runs once A and B are loaded (300ms debounce) for up to 200,000 combined faces; heavier meshes skip live preview and are computed only when you click the boolean button.
Which boolean engine does it use?
manifold-3d (Apache-2.0, WASM) as the primary kernel and three-bvh-csg (MIT) as the fallback for non-manifold input — the page always tells you which kernel produced your result.
Examples
- Upload meshes A/B → preview on page → union/subtract/intersect → download STL
Supported formats
Limitations
- The manifold kernel requires oriented manifold input (triangle soup is auto-welded); non-manifold inputs automatically fall back to the BVH kernel — that result is not guaranteed watertight, so run Mesh Doctor first.
- Live viewport preview recomputes with the manifold kernel (BVH fallback) on a 300ms debounce once A and B are loaded; meshes over 200,000 combined faces skip live preview and are computed only by the button.
- Best results on watertight meshes.
- Denser meshes take longer — simplify first for heavy models.
- Exports binary STL (materials are dropped).
- Everything runs locally in your browser; nothing is uploaded.
Privacy
Privacy first: this tool runs entirely in your browser — your input and files never leave your device, and everything is cleared when you close the page.