Fast STL Viewer

Fast STL Viewer brings professional-grade STL inspection and measurement to your Android device. Engineers, dental technicians, medical device teams, jewellery designers, and quality control inspectors worldwide rely on this app to catch defects before they become costly failures — tools that once required a desktop workstation now fit in your pocket.

Wall thickness analysis is at the heart of this viewer. A color-coded heatmap (red → yellow → green) maps thickness across your entire model, spotting thin walls and weak points before they cause print failures. The printability dashboard runs four automated mesh checks — open edges, flipped normals, non-manifold geometry, and degenerate triangles — with an interactive 3D overlay that highlights each issue directly on your model. Normal visualization lets you inspect per-face normal vectors with adjustable length, color, and thickness to verify surface orientation and diagnose reversed faces. Cross-section slicing with adjustable X, Y, Z cutting planes reveals internal geometry without splitting the file.

Measurement capabilities cover everything you need on site or in the field. Tap two points for point-to-point distance, calculate volume and surface area with your choice of units (mm, cm, in), and check bounding box dimensions in all three axes. The properties panel displays triangle count, full geometry stats, and dimensional data at a glance. Choose from five rendering modes — shaded, wireframe, combined, point cloud, and normals — plus six standard views (top, bottom, left, right, front, back) with orthographic projection for accurate dimensional inspection. Automatic detection identifies unconnected components within a single file, instantly color-coded for assembly review. Open boundary detection flags non-watertight geometry before printing.

Workflow is built for real-world use. Load multiple STL files for side-by-side comparison, open from Gmail, Google Drive, WhatsApp, or any file manager, and share STL files directly from other apps. The in-app file picker lets you select and open multiple files at once. Performance never lags — OpenGL ES 3.2 and native C++ with hardware-accelerated mesh analysis handle files with millions of triangles, supporting both binary and ASCII STL formats.

Engineers verify wall thickness on brackets and housings before manufacturing. 3D printing teams catch open edges and thin walls that would cause failures. Dental professionals inspect crowns and aligners with precision. Medical device teams review implants and prosthetics. Jewellery designers check filigree and prong settings before casting.

Try any Pro feature free by watching a short video to unlock 1-hour access. Upgrade to Pro with Fast STL Viewer to keep all inspection and measurement tools active.