Convert PLY to STL — From 3D Scan to 3D Printer

Usually, but check it first. PLY scan data frequently has mesh problems that transfer directly to the STL: holes from occluded scan areas, self-intersecting faces from registration errors, inverted normals, and non-manifold edges. Import the STL into your slicer and look for warnings — Cura shows an orange mesh-error icon, PrusaSlicer highlights problems in yellow/red. For automated repair, Meshmixer's Inspector tool (free) fixes most common issues in one click. If you want to fix before converting, use our [STL Repair Tool](/repair/stl) right in the browser.

If the file is under 150 MB, yes. But the resulting STL will be equally large — and most 3D printers don't benefit from more than 500K–1M triangles. The extra detail is below the printer's physical resolution. Decimate first in MeshLab (Filters > Remeshing > Quadric Edge Collapse Decimation, set target face count to 500K–1M), then convert the simplified PLY to STL. This gives you a smaller, faster-to-slice file with no visible quality loss in the print.

They're discarded — STL is geometry-only, no color support at all. If you need colored 3D prints, you have two options: (1) Convert PLY to 3MF instead, which supports per-vertex and per-triangle color, then use Bambu Studio or PrusaSlicer's color painting tools. (2) Convert PLY to GLB for web display where vertex colors are preserved natively.

Fix the PLY before converting — it's much easier to clean up in PLY format. In MeshLab: apply Laplacian Smooth (Filters > Smoothing > Laplacian Smooth, 2–3 iterations, lambda 0.5). For severe noise: use Statistical Outlier Removal in CloudCompare first, then Poisson Surface Reconstruction for a clean watertight mesh. Then convert the cleaned PLY to STL. Trying to smooth after conversion to STL is harder because STL's disconnected triangles make vertex-based smoothing less effective.

Yes, typically 1.5–2× larger. STL stores each triangle independently (50 bytes per triangle with duplicated vertices), while binary PLY uses indexed vertices (~24–32 bytes per triangle). A 5 MB binary PLY might become 8–12 MB STL. This is the tradeoff for universal slicer compatibility. If file size matters for sharing, consider converting to 3MF instead — it uses ZIP compression and is usually smaller than both PLY and STL.

Photogrammetry meshes have specific characteristics: very high poly count (often 5–20M faces), vertex colors from the photo texture, and potential holes where the camera couldn't see. Before converting: (1) Decimate to 500K–1M faces for printing. (2) Fill holes in MeshLab (Filters > Remeshing > Close Holes). (3) Check for non-manifold geometry. The vertex colors will be lost in STL, but the geometry prints fine. For color preservation, use PLY to 3MF instead.