Most G-code viewers haven't changed in a decade. Here's what the data actually shows:
The problem is real:
NCViewer gets ~94K monthly visits yet users still complain about animation speed control being completely broken, and gcode.ws openly admits it's "slow, memory hungry" on their own homepage SimilarwebOnline GCode Viewer
The vast majority of NC viewers don't handle machine-specific G-code dialects they assume a generic dialect and silently ignore anything they don't understand, which means bugs slip through undetected CNC Cookbook
Every major alternative still requires either a file upload (privacy risk), a desktop install, or locks layer inspection behind a paid plan
The market is growing fast tooling isn't keeping up:
GCodex is a free, browser-based G-Code viewer and simulator. No upload required, no signup needed.
Features:
- 3D & 2D toolpath visualization
- Layer-by-layer inspection
- Works with CNC machines and 3D printers
- Supports Marlin, Klipper, and standard G-Code
- Faster and cleaner than NCViewer and gcode.ws
Just paste or load your G-Code file and instantly visualize your toolpaths. Perfect for makers, engineers, and hobbyists.
