Reduce STL File Size (Simplify Mesh)
Cut the triangle count of an STL file by a chosen percentage while keeping the shape. Useful for oversized 3D scans, slow slicers and upload limits. Runs locally in your browser.
How it works
- 1Drop the file
Large 3D scans and photogrammetry exports are typical candidates.
- 2Choose how much to keep
Start at 50%. Most scans look identical at 20–30% of the original triangle count.
- 3Simplify and compare
The preview updates; check details you care about, then download.
Details
Simplification (decimation) merges triangles in flat regions while keeping edges and curved details. This tool uses the meshoptimizer library, the same algorithm used in game engines, running in WebAssembly in your browser. Boundary edges are locked so open meshes keep their outline.
A binary STL is exactly 50 bytes per triangle, so halving the triangle count halves the file. Slicers do not benefit from more than a few hundred thousand triangles on a desktop printer; 3D scans often contain millions.
Accepted formats: STL, OBJ, 3MF, PLY, GLB, glTF
Frequently asked questions
More STL tools
- Get the Dimensions of an STL File
Drop an STL (or any 3D file) to read its exact width, depth and height, bounding box, volume, surface area and triangle count. Runs in your browser, nothing is uploaded.
- Convert STL ASCII to Binary (and back)
Convert a text (ASCII) STL into the compact binary STL that slicers load faster, or the other way round for inspection. Binary files are typically 4–5× smaller.
- Scale / Resize an STL File
Resize a 3D model by a factor, to an exact target dimension, or fix a model that came out 25.4× too small or too big because of inch/millimeter confusion.
- Repair an STL File
Weld duplicate vertices, remove degenerate triangles, recompute normals and get a report of open and non-manifold edges before you slice. Basic repair for common export problems.
- STL File Info: Binary or ASCII, Triangle Count, Header
Inspect what is inside an STL file: encoding, header text, triangle count, bounding box and whether the mesh is closed. Handy before sending a file to a print service.