STL Viewer & Maker: 3MF G-code

STL viewer, STL file viewer, 3D model viewer and OBJ viewer for 3D printing. Also a 3MF viewer and G-code viewer with layers.

Someone sent you a model and your phone can't open the file. LayerPeek opens it and tells you what matters before you print: will it fit your printer, how many plates it has, and what might go wrong.

✓ No account, no sign-in
✓ Works offline: your files are read on your phone and stay there
✓ Files up to 512 MB
✓ Optional Pro with a one-time purchase

★ OPEN THE FILE YOU WERE SENT
• STL, 3MF, OBJ and G-code files, plus sliced .gcode.3mf projects
• ZIP downloads from model sites: pick the part you want
• Open from WhatsApp, Google Drive, Downloads, an SD card or any app's Share button

★ WILL IT FIT YOUR PRINTER?
Pick your printer once. Every model shows whether it fits the bed, with the spare room in millimeters. If it doesn't fit as it sits, LayerPeek checks whether turning it would make it fit.

★ 3MF VIEWER FOR PROJECTS
Opens Bambu Studio and OrcaSlicer 3MF projects with their plates and filament colors. Sliced .gcode.3mf files show the print time, the grams of each color and the plate thumbnails your slicer saved.

★ G-CODE VIEWER, LAYER BY LAYER
• Drag the slider to step through the print layer by layer
• Extrusion and travel moves in different colors
• Print time and filament use, read from the file

★ MEASURE AND CHECK THE MESH
• Overall dimensions in millimeters
• Tap two points to measure the distance between them
• Mesh health: holes and open edges that can cause slicing trouble
• Overhang shading shows where supports are likely

★ 3D PRINT COST CALCULATOR
Price this plate: filament, electricity, machine time, labor, packaging and a failure buffer add up to a cost and a suggested price per part, with profit per plate and per print hour. For unsliced models the weight is an estimate of a typical print, so use it for planning.

★ PHOTO TO LITHOPHANE MAKER
Turn a photo into a lithophane, a print that shows the picture when light shines through it. Choose flat, curved, night-light or keychain, set the size and save an STL. Drawings can become a keychain, sign, stamp or cookie cutter.

★ MAKE PARTS THAT FIT
Pick a template, set the sizes in millimeters, see it on your printer's bed and save an STL or 3MF:
• Cases for ESP32, Raspberry Pi, Arduino and more, with a short fit test print
• Boxes with dividers, name tags, cable clips, spacers and washers
• Describe it: COSMO AI picks a template and fills in the sizes. AI design uses COSMO credits and needs an internet connection; every template also works by hand.

★ SHARE A VERDICT CARD
One image with the model, the fit check and the key numbers, for a friend, a customer or your print group.

★ FREE WITH ADS, OPTIONAL PRO
LayerPeek is free with ads. Optional Pro removes ads and adds extra templates, more printers and saved cost profiles. Only the words you type into COSMO AI leave your phone.

★ SUPPORTED FILES
.stl (binary and text) · .3mf · .gcode.3mf · .obj · .gcode · .zip

A file that won't open? Email us from the contact link on this page and tell us where it came from.

Recent changes:
• LayerPeek no longer shows up when you share a mix of photos and videos
• Lithophanes preview backlit, the way the print looks against light
• Every viewer tool fits on screen in landscape
• One entry per file in Recent files
• A ZIP with a single model opens it directly
• Filament cost uses your region's currency