Kept
- The exact geometry when no decimation is selected
- Shape and dimensions
- A binary STL that slicers load faster
Runs locally · no upload
Compress an STL file
Reduce the size of an STL in two ways: store the same triangles as a binary STL, and optionally remove a share of vertices to lower the triangle count.
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- 5 credits per file
- 60 free credits at signup
- See credits ↗
Drop a 3D file hereSTL, OBJ, PLY, GLB, glTF, 3MF or STEP · up to 100 MB · processed locallyYour file never leaves this browser.
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What changes in the conversion
Dropped
- ASCII formatting (when converting to binary)
- Detail, only if you enable decimation
- No colours or materials: STL never had them
Common mistakes
- Decimation above 30% can soften thin walls and embossed text.
- The tool refuses meshes above 250k triangles for decimation; binary conversion still works.
- A corrupted STL will fail to parse before any compression.
For 3D printing
- Prefer binary STL: it is 3–6× smaller than ASCII for the same mesh.
- If you decimate, check wall thickness and small holes before printing.
Drop the file — it is read locally, never uploaded.
Choose the options, then convert or compress.
Download the result and open it in your slicer or 3D software.
Frequently asked questions
Is binary STL smaller than ASCII?+
Yes. ASCII stores coordinates as text; binary stores them as 32-bit floats, typically 3 to 6 times smaller.
Does compression change the shape?+
Only if you enable decimation. With 0% decimation the triangles are identical, only the encoding changes.
How much can I save?+
An ASCII STL often drops by 70–85% when converted to binary. Decimation adds another 20–60% depending on the ratio and the mesh.
Need a model instead of a conversion?
Turn a photo, a drawing or a logo into a 3D model, then export it in the format you need.