twineconvert

free · in-browser · no upload

STL to PLY
Converter

Drop your STL file. We'll convert it to PLY right here in your browser, your file never leaves your device.

or drop your file

Select your file here to get started

or drop your file here.

Accepts .stl

nothing uploaded no file size cap no signup

How it works

Three steps. No upload, no signup.

  1. 1

    Drop your file

    Click the dropzone above or drag a STL from your desktop. Files of any size, there's no upload, so there's no upload limit.

  2. 2

    Convert in your browser

    The conversion runs entirely in this tab using JavaScript and WebAssembly. Your file never touches our servers, we don't have any.

  3. 3

    Download

    Get your PLY the moment the conversion finishes. Convert another, or close the tab.

Files stay on your device

Your file is never uploaded. The entire conversion runs in your browser using WebAssembly. We can't see what you convert because we have no server to see it.

No file size limit

Server converters cap free users at 1-2 GB and gate larger files behind a paid plan. Since nothing uploads, our limit is whatever your browser can handle.

Free, no signup, no ads on conversions

No account required. No watermark on the output. No queue. Drop a file, get a converted file.

Formats involved

About STL and PLY

STL, Stereolithography

STL is the lingua franca of 3D printing, every slicer (PrusaSlicer, Bambu Studio, Cura, Simplify3D) reads it. Files are unstructured triangle soup: no scene graph, no materials, no scale info, just vertices and triangles. The format is ancient (1987) and primitive but its simplicity is exactly why it's universal. Two variants: ASCII (human-readable, big) and binary (compact, what most software produces).

How to open

Every 3D printing slicer, every CAD/3D tool (Blender, FreeCAD, Fusion 360, SolidWorks, Tinkercad). Free viewers: ViewSTL, MeshLab, online STL viewers.

Full STL format guide →
PLY, Polygon File Format (Stanford Triangle Format)

PLY was designed at Stanford's 3D scanning lab by Greg Turk (1994) to store scanned geometry, and it remains the standard output of 3D scanners and photogrammetry pipelines (Meshroom, RealityCapture, COLMAP). A fully self-describing header declares elements and typed properties, so files can carry per-vertex normals, colors, and confidence values alongside positions. Three encodings exist and all are common: ascii, binary little-endian, and binary big-endian. Blender imports and exports PLY natively.

How to open

Blender (File > Import > Stanford PLY), MeshLab, and CloudCompare all open PLY, including point-cloud-only files. Windows 3D Viewer reads mesh PLYs. The ascii flavor is inspectable in any text editor.

Full PLY format guide →

Related tools

Convert other files to PLY

Convert your STL to other formats

FAQ

Common questions

Is this STL → PLY converter really free?

Yes. No signup, no watermark, no daily file count limit. Every conversion runs in your browser, your file never touches our servers because there are no servers.

Where does my file go when I convert it?

Nowhere. The conversion runs entirely in your browser using JavaScript and WebAssembly. Your file is never uploaded to our servers. We don't have any servers handling files, there's nothing for us to log, store, or accidentally leak.

What's the maximum file size?

Whatever your browser can hold in memory. Practically, this means a few hundred MB on most computers, significantly larger than the 1-2 GB caps that server-upload converters charge for. Very large files (multi-GB) may require closing other browser tabs first.

Why convert STL to PLY?

3D printing, feed an STL into your slicer to get G-code. 3D scan and photogrammetry output, both meshes and point clouds. The most common reason to convert is compatibility, PLY works in places where STL doesn't, or vice versa.

How do I open a STL file in the first place?

Every 3D printing slicer, every CAD/3D tool (Blender, FreeCAD, Fusion 360, SolidWorks, Tinkercad). Free viewers: ViewSTL, MeshLab, online STL viewers.

Does this work offline?

Once the page is loaded, the conversion itself runs entirely offline. The first time you use a tool, your browser downloads the conversion library (a one-time cache). If you reload while offline, the page won't load, but you can install the site as a Progressive Web App for full offline use.

Can I convert multiple files at once?

Single file at a time for now. Batch conversion is on the roadmap, for now, drop one file, download the result, then convert the next.