Best free 3D viewers in 2026

Open3D Viewer — open3d.app/viewer

Web-based 3D viewer that runs in any modern browser. Supports STL, GLB, GLTF, OBJ, STEP, IGES, 3MF, FBX, DAE, PLY, USDZ, DXF and a few more. File never leaves the device.

Pros: no install, no sign-in, broad format support, light and dark themes.

Cons: very large files (300 MB+) hit browser memory limits — native is better for those.

gltf.report

Free, web-based, focused on glTF and GLB inspection. Shows you the scene graph, mesh details, material properties, extension list, compressed/uncompressed sizes.

Pros: best for debugging GLB files, very technical detail.

Cons: only handles glTF/GLB, less of a casual viewer.

Khronos glTF Sample Viewer

The official reference implementation of the glTF spec. Highest fidelity GLB rendering you can get in a browser.

Pros: definitive PBR accuracy, supports every glTF extension.

Cons: glTF/GLB only, dev-tool feel.

Open3D Viewer (free, ad-supported)

Native app on iOS App Store and Google Play. Handles the same formats as the web version with better performance on big files. AR preview on Android via Scene Viewer for GLB. Files open from email, Files, share sheet, anywhere.

Pros: wide format support, native performance, AR on Android.

Cons: ad-supported (banners, occasional interstitials).

Fast STL Viewer (Android)

Minimal — just STL — but very fast for huge files. Worth installing if you mostly receive STL.

Pros: handles enormous STLs without crashing.

Cons: STL only.

Built-in (USDZ on iOS, Scene Viewer on Android)

iOS Quick Look opens USDZ natively with AR. Android's Scene Viewer (Play Services) opens GLB with AR. For those two formats, the OS-native experience is the smoothest.

Pros: zero-install, OS-integrated AR.

Cons: only one format each. STL, OBJ, STEP need a third-party app.

MeshLab

Open-source, cross-platform mesh viewer and processor. Reads dozens of formats. Has measurement, cleanup, simplification, format conversion tools.

Pros: incredibly powerful for mesh work, free, mature.

Cons: UI feels like 2010, learning curve for casual users.

FreeCAD

Full parametric CAD that opens STEP, IGES, BREP natively with proper B-rep handling. Also reads STL and OBJ. Best free choice if you receive CAD files and want to inspect or edit them, not just view.

Pros: only free tool with real STEP / IGES kernel support.

Cons: heavy install, parametric CAD UI.

Blender

Free, open-source 3D suite. Reads GLB, OBJ, STL, FBX, DAE and many more. Not really a "viewer" but anything you'd want to do — view, modify, convert, render — Blender does.

Pros: ultimate flexibility, free, actively developed.

Cons: heavyweight, steep learning curve if you only want to look at a file.

eDrawings (free viewer from Dassault)

Free official viewer for SolidWorks-family files plus STEP and IGES. Excellent quality.

Pros: reference-quality STEP and DWG rendering.

Cons: Windows/Mac only, no Linux.

Cad Assistant (Open Cascade)

Free cross-platform viewer for STEP, IGES, BREP, OBJ and several others. Lightweight, has measurement tools, converts to STL.

Pros: lighter than FreeCAD, good for STEP / IGES, runs on mobile too.

Cons: not as full-featured as paid CAD viewers.

For 3D printing

You don't need a separate viewer — the slicer is the viewer. Bambu Studio, PrusaSlicer, OrcaSlicer and Cura all open STL/3MF and let you inspect, measure, repair before slicing. Free, no compromises.

For point clouds (PLY, PCD, LAS)

CloudCompare (free, open-source) is the standard. Handles huge point clouds, has registration, segmentation, comparison tools.

For AR preview / shopping demos

Google's <model-viewer> web component for embedding on your own page. Sketchfab embed for public showcases. Both free.