STL to PLY Converter

Hand STL files to MeshLab, CloudCompare or a scanning pipeline as compact binary PLY with shared vertices.

  • Files stay on your device
  • Free, no sign-up
  • Units and up axis handled
  • Batch and .zip

Drop an STL file to convert

One file, many, or a .zip

In: STL · STEP · IGES · OBJ · 3MF · GLB · glTF · PLY · FBX · DAE · 3DS · AMF · VRML · ZIP

Converted on your device. Nothing is uploaded.

    How to convert STL to PLY

    1. Drop your STL files

      Drop one or more .stl files, binary or ASCII, or a .zip of them.

    2. Check the preview

      The model appears at the size and orientation it will have. Fix the file units, up axis or size under Size, units and orientation if needed.

    3. Choose PLY options

      Binary little-endian PLY with vertex colors when the model has them. Pick the up axis your next tool expects.

    4. Convert and download

      One file downloads straight away. A batch gives a download per file and one .zip of all of them.

    What carries over from STL to PLY

    Worked out from what each format can store and what this converter writes. Nothing is changed silently: the preview shows the size and orientation before you download.

    Geometry Every triangle is kept at full precision.
    Color STL has no color to carry. The PLY comes out uncolored.
    Units PLY stores no units. The numbers stay in the unit the STL was read in (millimetres); you can change that in the options.
    Orientation Kept the way the STL had it. Switch to Y up (Blender, game engines) or Z up (slicers, CAD) in the options.
    Objects Merged into one mesh: PLY has no objects.

    STL to PLY: what actually happens

    Some mesh-processing and inspection tools work best with PLY. The converter welds the STL's loose corners into shared vertices and writes binary little-endian PLY, typically under half the size of the STL.

    Units and orientation pass through unchanged, since neither format fixes them: an STL in millimetres becomes a PLY in millimetres, Z up. Switch the up axis in the options if the next tool expects Y up.

    STL at a glance

    Stereolithography (Standard Triangle Language) · .stl

    Stores
    Loose triangles: three corners and a normal each, binary or ASCII
    Color
    None in the standard
    Units
    None written; slicers assume millimetres
    Up axis
    Z, the slicer convention
    File size
    50 bytes per triangle in binary, about 5 times that as ASCII
    Opens in
    Every slicer, CAD tool and 3D app

    Created by 3D Systems in 1987 for the first stereolithography printers, STL is still the format every slicer and print service accepts. It describes a surface as a list of independent triangles, with no shared vertices, units, colors or scene structure.

    Open STL files in the viewer

    PLY at a glance

    Polygon File Format (Stanford Triangle Format) · .ply

    Stores
    Vertices with any properties, optional faces; ASCII or binary
    Color
    Per-vertex colors
    Units
    None; scanners usually write metres
    Up axis
    Varies with the scanner or app
    File size
    Binary is compact; ASCII is several times larger
    Opens in
    MeshLab, CloudCompare, Blender, scanning and photogrammetry software

    Greg Turk designed PLY at Stanford in the 1990s for 3D scan data, and it is still what scanners, photogrammetry tools and MeshLab write. It can hold a colored mesh or a bare point cloud, and Gaussian splat captures reuse it for splats.

    Open PLY files in the viewer

    Tips for STL to PLY

    MeshLab

    Welded PLY lets MeshLab's filters (smoothing, decimation, hole filling) work on a connected mesh.

    Comparing scans

    CloudCompare can compare the PLY against a scan to check a print's accuracy.

    ASCII PLY?

    Binary is smaller and read everywhere. MeshLab can re-save as ASCII if a tool needs it.

    STL to PLY FAQ

    Why convert STL to PLY?
    For tools that prefer PLY, for a welded mesh, or for a smaller file. PLY can also carry vertex colors that STL can't.

    Is the PLY binary or ASCII?
    Binary little-endian, the most compact and widely read form.

    Does it change the size?
    No. The numbers pass through unchanged.

    Is the converter free? Are there limits?
    Free, with no sign-up, watermark or file count limit. Batches and files of a few hundred MB work on most laptops; the only limit is your device's memory.

    Are my files uploaded?
    No. Files are read and written by JavaScript and WebAssembly in your browser and never sent to PrintPal. The STEP and IGES reader is the only extra download, once, from a public CDN.