PrintForge is a free 3D model editor for 3D printing that runs completely in your browser. There is no account, no installation and nothing to wait for: open the page, build or import a model, download the file and slice it.
Quick start
- Click a shape in the Shapes panel. It lands on the build plate.
- Drag the arrows to move it, or type exact values in the Selection panel. Press E to rotate and R to scale.
- Shift-click a second object and use Union, Cut or Intersect to combine them. Cut removes the later-selected objects from the first one.
- Press P or click Place on plate: the selection is centred on the bed and lowered until it rests on it, ready to print.
- Choose your printer in the status bar so you can see the build volume.
- Click Download and pick STL or 3MF. Open the file in your slicer.
Keyboard shortcuts
| W E R | Move, rotate, scale |
| P | Place selection on the plate (centre and drop) |
| G | Toggle snapping (1 mm or 1/16 in, 15°) |
| F / H | Zoom to fit / home view |
| Arrows, PgUp PgDn | Nudge selection by 1 mm or 1/16 in (hold Shift for 10 mm or 1 in) |
| Shift + click | Add to selection |
| Ctrl + A | Select all |
| Ctrl + D | Duplicate |
| Del | Delete |
| Ctrl + Z / Shift + Ctrl + Z | Undo / redo |
| Ctrl + I / E | Import a file / download STL |
| Ctrl + S / O | Save / open a PrintForge project file |
| Left drag · Right drag · Wheel | Orbit · pan · zoom the camera |
Files and formats
Import
Drop STL, OBJ or 3MF files anywhere on the page, or use Import. Files are read in millimetres with Z pointing up, the same convention slicers use. A model that arrives tiny was probably saved in inches or metres; the import message offers to convert it, and the Size fields work for everything else.
Download
- STL (binary) is accepted by every slicer, including Bambu Studio, PrusaSlicer, OrcaSlicer, Cura and Chitubox.
- 3MF keeps each object separate and stores its colour, which is handy for multi-part or multi-colour prints.
- OBJ is a plain-text mesh for other 3D tools.
Mirrored objects are written with corrected face orientation, so the slicer sees a proper solid.
Project files
Save keeps the editable version of your work, including shape settings, as a small JSON file. The current model is also stored automatically in this browser so it survives a reload.
Millimetres or inches
PrintForge starts in inches for visitors from the United States, Liberia and Myanmar and in millimetres everywhere else; the choice you make in the mm / in toggle in the status bar is remembered on this device. Every field, the build plate grid and the snapping steps follow the choice: 1 mm and 10 mm steps in metric mode, 1/16 in and 1 in steps in imperial mode. Files are always downloaded in millimetres, because that is what every slicer expects from STL, 3MF and OBJ files. Imported files are read as millimetres too; if a model arrives tiny because it was saved in inches or metres, the import message offers a one-click conversion.
Which printers are supported?
Any printer that reads STL, 3MF or OBJ. The printer list only sets the size of the build plate you see, with presets for Bambu Lab, Prusa, Creality, Anycubic, Elegoo, Flashforge, Sovol and Voron machines plus common resin printers. Pick Custom size to type your own dimensions.
Tips for models that print well
- Use Place on plate before downloading so the model sits centred and flat on the bed. Lower only keeps the sideways position and lowers each object by itself; Centre only moves sideways and keeps the height. Objects highlighted in red stick out of the build volume.
- Booleans need closed, watertight shapes. Every built-in shape qualifies and the result is watertight too. An imported mesh with holes is combined by a fallback engine instead; PrintForge tells you when that happens, and the slicer may need to repair the file.
- Fewer segments on cylinders and spheres keep files small; 64 segments are plenty for parts under 50 mm.
- Text prints best at 3 mm or more thickness and 10 mm or larger letter height.
Your files stay on your device
Everything happens in your browser. Models are never uploaded to a server, and there is no account, tracking pixel or sign-up wall. The only network requests load the app itself and the open-source libraries it is built on.
PrintForge is built with three.js, Manifold and three-bvh-csg. Units are millimetres, Z is up.