G-code viewer & editor

Preview G-code layer by layer in 3D, check print time and filament use, and insert a filament change, pause or temperature change at any layer. Files never leave your browser.

Your G-code preview will appear here

How to view G-code online

  1. Drop a .gcode file from PrusaSlicer, OrcaSlicer, Bambu Studio, Cura or any other slicer into the box above. It is read locally in your browser — even files of a few hundred megabytes.
  2. The toolpaths are drawn in 3D and colored by feature: outer wall, inner wall, infill, top/bottom, bridges, support and skirt/brim. Travel moves are hidden until you turn them on.
  3. Drag the layer slider to see the print build up, or tick Only this layer to inspect one layer at a time.
  4. Check the stats: layer count, layer height, size, filament length and weight and the estimated print time.
  5. Optionally insert a filament change (M600), a pause, custom G-code or a temperature change before any layer, then download the modified file.

How print time and filament are estimated

Every move is added up using its feedrate, with a small extra time for slowing down at corners, so the estimate is close to what slicers report for most printers. Filament length is the sum of all extrusion, and weight uses the filament diameter and the density of the chosen material (PLA 1.24, PETG 1.27, ABS 1.04 g/cm³). When the slicer wrote its own estimates into the file, they are shown as well.

Adding a color change with M600

M600 tells Marlin, Prusa and many other firmwares to park the nozzle, unload the filament and wait for you to load a new one. Inserting it before a layer is an easy way to make two-color signs, logos and keychains on a single-nozzle printer. Klipper printers usually need a PAUSE macro or an M600 macro instead.

FAQ

How do I view a G-code file online?

Drop your .gcode file above. The toolpaths are drawn in 3D and the layer slider lets you inspect every layer. Nothing is uploaded.

How can I estimate print time and filament from G-code?

The viewer sums every move with its feedrate and the extruded filament. It shows length, weight for PLA, PETG or ABS, and the slicer's own estimates when available.

How do I add a filament change (M600) at a specific layer?

Pick the layer where the new color should start, choose Filament change (M600), click Add and download the modified G-code. The command is inserted right before that layer begins.

Can I change the nozzle or bed temperature partway through a print?

Yes. Enter a layer and the new hotend and/or bed temperature. M104 and M140 commands are inserted before that layer.

Does it work with .gcode.3mf or .bgcode files?

Not yet — the viewer reads plain-text G-code. Export plain .gcode from your slicer (in PrusaSlicer, turn off binary G-code in the printer settings).