G-Code Viewer & CNC Simulator
A free, browser-based G-code viewer and CNC simulator with real-time 3D visualization and support for massive files. No install required.
Features
Everything you need for G-code analysis
3D Visualization
Real-time 3D rendering of toolpaths.
Large File Support
Handles files with millions of lines using optimized rendering.
Animation
Animate the cutting process so you can see the toolpath in the order it will be cut.
Keyboard Shortcuts (Coming soon...)
Keyboard shortcuts for navigation and control.
Syntax Highlighting (Coming soon...)
Color-coded G-code with error detection and line-by-line navigation.
Free Online G-Code Viewer
CutViewer is a free, browser-based G-code viewer and CNC simulator. Upload your .nc, .gcode, .tap, or .ngc files and instantly see a 3D visualization of your toolpaths before running them on your machine.
Whether you're running a hobby 3018 CNC, a GRBL-based router, or a full-size mill, CutViewer helps you verify your G-code programs before cutting. Catch errors, check toolpath order, and confirm your feeds and speeds are correct — all without leaving your browser.
Supported G-Code Commands
CutViewer supports standard G-code commands including rapid moves (G00), linear interpolation (G01), circular arcs (G02/G03), plane selection (G17/G18/G19), inch and metric units (G20/G21), absolute and incremental positioning (G90/G91), and work coordinate systems (G54-G59). View the full list in our documentation or check the G-code reference guide.
Works with Any CNC Machine
CutViewer reads standard G-code, so it works with virtually any CNC machine — 3018 Pro, Shapeoko, X-Carve, MPCNC, Onefinity, or any machine running GRBL, Mach3, Mach4, LinuxCNC, or other standard G-code controllers.
Ready to simulate your G-code?
No installation required. Works in any modern browser.
Launch CutViewer Now