Every 3D model tool, in one place.

STL, OBJ, PLY and GLB

STL describes only the surface of a model, as a mesh of triangles, with no colour or materials. That simplicity is why every slicer and 3D printing service accepts it. OBJ also stores the surface and can carry texture coordinates, and almost every 3D editor opens it. PLY is common from 3D scanners and can hold a colour for each point.

GLB is the single file version of glTF, the format built for showing 3D on the web. Browsers, AR viewers and game engines load it directly, so convert a printable STL to GLB when you want to show the model on a page.

What changes in a conversion

Mesh to mesh conversions run on trimesh, an open source geometry library. The model keeps its size and position. Faces with more than three corners are split into triangles where the target format needs it, and colour and materials are dropped when the target is STL, because STL cannot store them.

Check the units in your slicer after converting. An STL file carries no unit, so a model drawn in inches arrives about 25 times too small when the slicer assumes millimetres.

CAD files

STEP files from CAD programs describe exact surfaces, not a mesh. Turning one into an STL means choosing how finely to approximate each curve, a decision a converter should not make for you, so the STEP to STL page is a step by step guide using FreeCAD, which is free, with the settings that matter.

Privacy and limits

Model conversions run on FileWhirl's own server, and uploads are deleted after 1 hour. Each tool's page says where its file goes, nothing is passed to a third party converter, and there is no watermark.