G-code Previewer & Layer Inspector
Drop a G-code file and scrub through it layer by layer. Moves are color-coded by type - outline, fill, and support - so you can spot problems before you print. Print time and filament estimates are read straight from the file. Nothing uploaded.
Drop your G-code file here
or
.gcode .gc .g .gco accepted - parsed locally, nothing uploaded
Learn more: G-code preview and layer inspection
Why G-code preview matters before printing
A 3D print that fails 6 hours in wastes filament, machine time, and your time. Most failures are visible in a layer-by-layer G-code preview: missing support structures, a first layer that does not stick because the slicer calculated the wrong Z offset, infill density that is clearly wrong, or a tall object that will almost certainly knock itself off the bed before it finishes. PrusaSlicer and Bambu Studio have built-in previews, but if you are working with G-code that was generated elsewhere or modified after slicing, you need an external viewer.
How the previewer works - layer-by-layer inspection
Drop your G-code file and the previewer parses all movement commands instantly. Use the slider to scrub through layers. Moves are color-coded by type: blue for perimeters (outer walls), green for infill, orange for support structures, and gray for travel moves. Print time and filament estimates are read straight from the slicer comments in the file header.
Supported slicers and file formats
The previewer works with G-code from Cura, PrusaSlicer, Bambu Studio, SuperSlicer, IdeaMaker, and most other slicers. It reads standard G0/G1 movement commands and parses print time and filament estimates from slicer comments automatically. Accepted file extensions: .gcode, .gc, .g, .gco.
FAQ
Is my G-code file uploaded to a server?
No. G-code is read and rendered entirely within your browser. The file never leaves your device. This means you can safely preview proprietary designs, client files, or confidential product prototypes.
What does color-by-feature mean?
Moves are colored by what the printer is doing: outer wall (perimeter), fill pattern (infill), support structures, or rapid positioning (travel). This makes it easy to spot problems like inadequate support, wrong infill pattern, or excessive travel moves.
Can I zoom or pan the canvas?
The preview auto-scales to fit the print bed. You can adjust line width (1x, 2x, 3x) to make thin features more visible, and toggle travel moves on or off to reduce clutter.