Meet the STL Simplifier & Smoother
Reduce the triangle count of an STL, OBJ, 3MF or scan with quadric edge collapse, set a maximum deviation, and smooth rough meshes with volume-preserving.
- Free to use
- No signup
- Nothing to install
- Runs in your browser
A 400,000-triangle scan reduced to 20% keeps about 80,000 triangles; a smooth sphere or torus can lose 90% of its triangles with under 2% volume change, while a cube stops at 12 triangles because every further collapse would break its corners.Open the STL Simplifier & Smoother
Illustration. Open the tool for the real thing.
See it in action
The STL Simplifier & Smoother with sample data entered and the result showing.
What is the STL Simplifier & Smoother?
Photogrammetry scans, sculpts and exports from some CAD programs can contain millions of triangles — files too big to upload, slow to slice and heavy to open. This tool reduces the triangle count with quadric-error edge collapse, the same family of algorithm used in professional mesh software: it repeatedly removes the edge whose loss changes the surface least, so flat regions lose triangles first and curved, detailed regions keep them. You choose how many triangles to keep and, optionally, a maximum surface deviation in millimetres so the reduction stops before it distorts the part.
A second mode smooths rough, noisy or stair-stepped meshes using Taubin (λ|μ) smoothing, which relaxes vertices without the shrinkage of plain Laplacian smoothing, and can leave sharp edges alone above an angle you choose. You can run both in one go. The result shows triangle count, file size, volume change and whether the solid is still watertight, and you can step back to the original at any time. All processing runs in a background thread in your browser, so the page stays responsive and the model is never uploaded.
3 steps to your result
Open the tool and follow along. Nothing to install.
What you get
Removes the least important edges first; open-mesh boundaries are protected.
Stops early rather than distort the surface beyond your tolerance.
Smooths noise without shrinking, with a sharp-edge angle threshold.
Refuses face flips and non-manifold pinches; reports watertightness and volume change.
AZRS tools are free to open and use.
It opens in your browser, so there is nothing to download.
Used for
Pick one to see how it fits.
How it compares
A plain look at this tool next to the usual alternative.
| This 3d tool | Desktop software | |
|---|---|---|
| Install | Nothing to install | Usually an app or program to install |
| Account | No signup | Depends on the product |
| Cost | Free to use | Free or paid, depends on the product |
| Where it runs | In your browser tab | On your computer |
Questions people ask
Does reducing change the size?
Overall dimensions stay within the deviation shown; volume change is reported.
Why did it stop early?
The deviation limit or a topology safety check blocked further collapses.
Does it keep colour/texture?
No — output is plain geometry (STL/3MF/OBJ/PLY/GLB).
Is it private?
Yes, nothing is uploaded.
How do I use the STL Simplifier & Smoother?
1. Drop in a dense STL, OBJ, 3MF or scan. 2. Choose Reduce, Smooth or both and set the strength. 3. Optionally set a maximum deviation in mm. 4. Check the result in the viewer and download it.
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Try the STL Simplifier & Smoother now
Reduce the triangle count of a heavy STL/OBJ or smooth a rough scan without shrinking it. Free to use.
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