G-code Viewer
Visualize a CNC or 3D printer G-code file's toolpath.
Drag and drop a G-code file, or click to choose one
Supports .gcode, .nc, .ngc, .tap, .cnc files
Usage examples
Previewing a CNC program before running it
Check that a CAM-generated G-code file's toolpath looks right in your browser before loading it onto the machine.
Reviewing a 3D printer's print path
Upload a slicer-generated G-code file to see how the print head moves and confirm the path stays within the bed.
Telling rapid moves apart from cutting moves
Gray dashed lines mark rapid (non-cutting) moves and solid blue lines mark feed (cutting/printing) moves, so you can spot unnecessarily long rapid travel at a glance.
Frequently asked questions
Is my uploaded file sent to a server?
No. Reading and parsing the file happens entirely in your browser and is never sent to a server.
Which G-code commands are supported?
Linear moves (G0, G1) and arc moves (G2, G3) are supported, recognizing both absolute (G90) and relative (G91) positioning. Other M-codes and similar are ignored since they don't affect the toolpath.
Does it show Z-axis (height) changes?
Currently it shows a top-down 2D path in the X-Y plane only. The bounding box stats include the total Z-axis range moved.
How accurate is the estimated time?
It's a simple sum of each segment's length divided by its programmed feed rate (F). It doesn't account for acceleration/deceleration, so actual machine time may differ.