Open3D vs Forge Slicer

Open3D Viewer is the fastest free 3D model viewer for STL, GLB, OBJ, FBX, STEP, DXF, USDZ, PLY, 3MF, GLTF, IGES, DAE and 3DS files. Open any 3D file in seconds, view it in AR with Apple Quick Look, and check it for 3D printing — no account, no sign-up, no cloud upload. Your files never leave your iPhone or iPad. Whether you're a 3D-printing hobbyist checking an STL before slicing, a 3D artist previewing a GLB or FBX, or a CAD user opening a STEP or DXF, Open3D Viewer opens it instantly — without the paywalls and login screens other 3D viewers force on you. SUPPORTED 3D FILE FORMATS • Mesh: STL, GLB, GLTF, OBJ, PLY, 3MF, FBX, DAE, 3DS, USDZ • CAD: STEP / STP, IGES / IGS, DXF Export & convert Turn OBJ, PLY, 3MF, FBX, DAE, 3DS and more into STL for 3D printing or GLB for sharing. Files save straight to your Downloads folder — no extra apps, no online converter, everything happens on-device. A 3D VIEWER THAT DOES THE BASICS RIGHT • Open files from Files, email, downloads, or any "Open with" menu • Smooth orbit, pan and zoom touch controls • Render modes: solid, wireframe, X-ray, textured, matte • Wireframe overlay — see the geometry on top of the rendered surface • Preset camera views (front, side, top, perspective) • Light and dark themes • 5 background colours + 6 HDRI lighting environments (studio, sunset, dawn, dusk, dark, white) • Play built-in animations • View 3D models in AR via Apple Quick Look (USDZ) • Capture a screenshot or a rotating GIF and share it • Recent files with auto-generated thumbnails • Full model specs: triangle count, vertices, materials, textures, bounding box BUILT FOR 3D PRINTING • Print-readiness check: manifold / watertight detection, overhangs, wall thickness • Bed-fit check for popular printers (Bambu A1, Prusa MK4, Ender 3, Bambu X1C) • Rough weight, filament length and cost estimates • Measure distances on the model • Cross-section / clipping plane to inspect interiors • Scale and resize tool • Convert and export between GLB and STL LOCALIZED The interface automatically follows your device language. Currently available in English, German, Spanish, French, Portuguese, Hindi, Japanese, and Chinese. NO ACCOUNT. NO CLOUD. NO NONSENSE. • No sign-up, ever • 100% on-device. Works offline. • We never read, scan, or upload your files • We don't track which files you open The STL viewer and GLB viewer that makers, 3D artists and engineers actually want: clean, fast, and local. Measurements and print-readiness figures are estimates, not a replacement for a slicer or proper measuring tools. See the in-app Disclaimer. Open3D Viewer is an independent app and is not affiliated with the Open3D open-source library at open3d.org. All trademarks belong to their respective owners. Privacy policy: https://open3d.app/privacy.html

Forge is a complete 3D printing slicer that runs entirely on your iPhone. Import an STL, place it on the bed, scale and rotate it, slice it, preview the toolpaths layer by layer, and export G-code to your printer — no laptop, no account, no upload. NOTHING LEAVES YOUR PHONE Forge contains no networking code at all. Your models are parsed, sliced and exported on the device. There is no account to create, no cloud sync, no analytics and no ads. That is not a setting you switch on — it is how the app is built. A REAL SLICER, NOT A VIEWER - Draft, Standard and Fine presets to start from - Layer height and first-layer height - Wall count, top layers and bottom layers - Five infill patterns — Lines, Grid, Triangles, Gyroid and Concentric — with adjustable density - Nozzle and bed temperature, with a separate first-layer temperature - Print speed control - Automatic retraction and a first-layer skirt - True top and bottom surface detection, so solid faces land where they belong - Filament length, weight and estimated print time before you commit SET UP FOR YOUR PRINTER Bed width, depth and maximum height. Nozzle diameter. 1.75 mm or 2.85 mm filament. Heated or unheated bed. Origin at the corner or at the bed centre for delta machines and some cartesians. SEE IT BEFORE YOU PRINT Preview the generated toolpaths layer by layer. Scrub through the model and see exactly where walls, infill and solid surfaces go — before you commit filament to it. EASY TO GET MODELS IN Open an STL from Files, iCloud Drive, AirDrop, Mail or Safari — Forge appears in Open With across the system. Six sample models are built in, including a 20 mm calibration cube, so there is something to slice the moment you install it. A built-in list of model sites points you at Printables, MakerWorld, Thingiverse and Thangs. EXPORT ANYWHERE AirDrop G-code straight to your Mac, email it, or save it to Files and copy it to a USB drive or SD card. You can also export the edited mesh back out as an STL, with your scale and rotation baked in. SHORTCUTS Import, slice and open models from the Shortcuts app. BUILT FROM SCRATCH Forge's geometry kernel was written specifically for this app and is checked against a verification suite of solids with hand-computed answers. Integer-precision arithmetic means contours close reliably instead of almost closing. Forge is free. No in-app purchases, no subscriptions, no ads.