3D models rarely show up in the one format you need. These tools open, inspect, shrink and convert them between the formats used by game engines, 3D printers, AR viewers and CAD tools, without uploading anything.
GLB/GLTF is the web and AR standard, OBJ and FBX are common in game engines and 3D software, STL and 3MF drive 3D printers, PLY stores scanned point clouds, USDZ powers Apple's AR Quick Look, and DAE (Collada) still shows up in older pipelines. Convert between them without installing a 3D suite.
Every model is parsed, rendered and re-exported locally using three.js running in your browser; files are never uploaded to a server. Large or animated models depend on your device's memory and GPU, so very heavy scenes may take a moment or need to be simplified first with the compressor.
Generate or scan a model, convert it to GLB for a quick web preview in the 3D model viewer, compress or resize it to hit a target polygon or file-size budget, then convert it one more time to whatever format the destination app (a game engine, a printer slicer or an AR viewer) actually expects.