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3DAI
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STL Simplifier: Fewer Triangles, Same Shape

A 3D scan, a sculpt or an AI-made model can carry millions of triangles that a print, a slicer or a game engine never needs. Drop the STL here, set how much of the mesh to keep and watch the preview change. Flat and gently curved areas lose triangles first, while edges and the outer size stay put. When it looks right, download the simplified STL. Everything runs on your device.

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How to use it

  1. 1

    Load the mesh

    Drop a binary or ASCII .stl on the box or click to choose one.

  2. 2

    Set the amount

    Keep a percentage of the triangles or type an exact count. Start at 50% and go lower while the preview still looks the same.

  3. 3

    Check the result

    Flip the preview between before and after, and read the triangle count, the new file size and the largest change from the original surface in mm.

  4. 4

    Save the STL

    Download the simplified mesh as a binary STL, ready for your slicer, CAD or game engine.

What to know before you convert

  • Simplifying removes detail. Tiny text, sharp creases and fine surface texture are the first to soften, so check the preview before you save.
  • Overall width, depth and height are kept: the points at the extremes of the model are locked.
  • Duplicate corners are welded first so the mesh can be simplified. Holes in the mesh are kept as they are; use the STL repair tool to close them.
  • Very low targets can be impossible without tearing the shape. The panel then says how far it got.
  • STL only, up to about 100 MB depending on your device memory. For GLB, OBJ or FBX with textures, use the 3D model compressor or LOD generator.

Don't have a model?

Create one with AI from a photo, a sentence or a sketch. The generators use credits; this converter is free and stays in your browser.

Image to 3D →Turn one photo into a textured 3D model.Text to 3D →Describe an object and get a GLB.Sketch to STL →Draw it, get a printable model.

Frequently Asked Questions

It rebuilds the mesh with fewer triangles. Short edges are collapsed so neighbouring triangles merge, and each step is measured so the surface moves as little as possible. The result is a lighter file that looks and prints almost the same.
It depends on the model. Scans and sculpts often keep their look at 10% to 25% of the triangles; a low-poly CAD part may have little to remove. Watch the largest deviation number: under about 0.05 mm it is smaller than a printed line.
Yes. Decimate, simplify and polygon reduction all mean removing triangles while keeping the shape. This page uses the open-source meshoptimizer edge-collapse simplifier, the same family of method used in Blender and MeshLab.
A closed mesh stays closed: the simplifier merges triangles but does not open new holes. A mesh that already had holes keeps them.
Zipping makes the download smaller but the slicer, viewer or engine still has to handle every triangle. Simplifying lowers the work itself, so the file opens, slices and renders faster.
No. The page reads the file and converts it inside your browser with the open-source three.js library. Nothing is sent to our servers, there is no account, and no credits are used. Closing the tab discards everything.