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How to Convert 3D Models Online (STL, OBJ, GLB & More)

You have a 3D model in one format, but the tool you are using expects another. A slicer wants STL, a web viewer wants GLB, an editor wants OBJ, and your 3D scan came out as PLY. Converting between them should not require installing heavyweight CAD software - and it does not.

Here is how to convert 3D models in seconds, which format to target, and how to do it without your files ever being stored.

Step 1: Know what you need

Pick your target format based on what you are doing:

  • 3D printing: convert to STL (or 3MF for colour and print settings)
  • Editing or rendering: convert to OBJ
  • Web pages or AR: convert to GLB
  • Scanning / research pipelines: convert to PLY or OFF

Not sure what each format is for? See our companion guide, 3D file formats explained.

Step 2: Choose the converter

Each conversion has its own dedicated tool. The most common ones:

Browse everything on the 3D & CAD tools page.

Step 3: Upload and download

  1. Open the converter for your source and target format.
  2. Upload your model - drag and drop or click to browse. Files up to 250 MB are supported.
  3. Download the result - conversion takes a few seconds and the geometry is carried over unchanged.

Will my model look different after converting?

The shape will not change - every vertex and face is preserved. What can change is the "extra" data a format carries. STL, for example, stores geometry only, so converting a textured or coloured model to STL keeps the shape but drops the colour and materials (there is simply nowhere in an STL to put them). Converting toward richer formats like GLB or 3MF has no such limitation.

Common problems and fixes

  • "My model has no colour after converting to STL." That is expected - STL cannot store colour. Use GLB or 3MF if colour matters.
  • "The file will not slice." Slicers want STL or 3MF. Convert from OBJ, PLY or GLB first.
  • "It will not load in my web viewer." Web and AR viewers expect GLB - convert your STL or OBJ to GLB.
  • "The conversion was rejected." The file may be corrupted or not a valid mesh. Re-export it from your source tool and try again.

Is it safe and private?

PrivConvert is built privacy-first. Every 3D conversion runs in an isolated, network-free environment, entirely in memory:

  • Your model is processed in server memory (RAM), never written to disk
  • It is deleted the instant the converted file is delivered
  • All transfers are encrypted with HTTPS
  • No account, no tracking, no file storage

Read more on our security page.

Start converting:
STL to OBJ OBJ to STL STL to GLB All 3D tools