// upload g-code → preview in 3D → pick layers → insert M600 → download · runs in your browser
No file handy? Quick height → layer calculator
Preview your G-code in 3D, add color changes and pauses
Upload a sliced .gcode file, rotate it in 3D, scrub through it layer by layer, and click the layers where you want to change filament color (M600) or pause the print to drop in a magnet or nut. The tool inserts the right command at each of those layers and lets you download the finished G-code — ready to print. The 3D view even shows your color bands. Everything runs in your browser; the file is never uploaded.
How do I pause a print to insert a magnet or nut?
Scrub to the layer where the cavity is covered, add a pause (with an optional LCD note like "insert magnet"), and download. The tool inserts a pause command — M601 (Prusa/Marlin), M0, or PAUSE (Klipper) — so the printer stops, you drop the part in, and resume to encapsulate it.
How do I add a color change to G-code without re-slicing?
Open your sliced file here, pick the layer (the 3D view and the layer preview show exactly where you are), add the change, and download. No need to go back into the slicer.
Is my file uploaded to a server?
No. Parsing, 3D preview and editing all happen locally in your browser. The file is kept only in your browser's storage (IndexedDB) so it survives a reload, and nothing is sent anywhere.
What is the M600 command?
M600 is the filament-change G-code in Marlin and Klipper: the printer parks, unloads and waits for you to load a new color, then resumes. This tool inserts it at the start of each layer you choose.