Pocket 3D: STL Viewer

Open any STL on your phone. Read real dimensions, volume and surface area, and check whether the mesh is watertight before you print it. Works completely offline.

Pocket 3D turns your iPhone into a proper STL viewer. Open a model, turn it over in your hand, and find out the things you actually need to know before you print it.

MEASURE YOUR MODEL Bounding size on every axis, plus volume, surface area and triangle count. Everything is measured in the file's own coordinate frame, so the axes match your CAD software or slicer. Sizes are shown in millimetres, the standard convention for 3D printing.

CHECK IF IT WILL PRINT In a closed mesh, every edge is shared by exactly two faces. Pocket 3D verifies that and reports the result. When a mesh is not watertight, the app withholds the volume figure rather than showing one, because on an open surface that number has no meaning.

VIEW FROM ANY ANGLE One finger orbits, pinch zooms, two fingers pan. Snap to isometric, top, bottom, front, back, left or right, and re-frame at any time.

MAKE IT READABLE Six model colours, four backdrops, and four shading modes: flat, smooth, wireframe and x-ray. X-ray fades the near surfaces so interior structure becomes visible.

OPEN FILES FROM ANYWHERE Binary and ASCII STL with automatic format detection. Open from the file picker, your recents, or share a file straight into Pocket 3D from another app. A sample model is bundled so you can try it immediately.

PRIVATE BY DEFAULT No servers, no account, no sign-up. Files are read on your device and never leave it. No analytics, no advertising, no tracking. Works with no internet connection.