G-code Viewer Online
G-code Viewer previews CNC and 3D-printing toolpaths in 3D, right in your browser. Drop a .nc or .gcode file — it renders automatically — and inspect the highlighted source, timeline playback…
Processing and data safety
Section titled “Processing and data safety”This tool runs entirely in your browser — your files are never uploaded to a server.
Input and output
Section titled “Input and output”- Formats: GCODE, NC, TAP, GCO, CNC, NGC
- Flow: G-code files → 3D toolpath preview with replay
How to use
Section titled “How to use”- Drop a .gcode / .nc / .tap file — the toolpath renders in 3D automatically (or click Load sample).
- Drag the progress slider to step through moves, click a source line to seek, or press Play for a timeline replay (0.5–8× speed; dragging pauses it, it stops at the end and replays from the start).
- Inspect the 2.5D material-removal simulation (depth-shaded, by last cutting tool, or stepped by Z depth layer — cumulative top-down coverage) and the tool legend/stats (view only, no output file).
Key details and limits
Section titled “Key details and limits”- Very large programs are parsed in full and may exhaust browser memory — the whole file is rendered, nothing is downsampled. Parsing runs synchronously on the main thread: the page may be briefly unresponsive while parsing and cannot be cancelled mid-parse.
- View only; no G-code is generated or modified, and playback is a motion preview only.
- Numeric readouts (stats, 2.5D simulation) are in mm — inch (G20) programs are converted at 1 in = 25.4 mm; the 3D canvas renders in the program’s original units.
Common use cases
Section titled “Common use cases”- Drop a .nc / .gcode file → 3D toolpath preview
- Click a source line to seek the toolpath · press Play for a 0.5–8× timeline replay