G-Code Viewer

• Inspect sliced .gcode before it reaches the printer
• A quick look at the toolpaths catches the wrong-profile print before it costs you a spool's worth of regret.

A sliced file is the last thing you check before committing several hours of printer time, and it is the one file your Mac cannot show you. G-code Viewer renders the actual toolpaths, so you can see the print rather than trusting the filename.

Thumbnails appear in your file browser automatically. Quick Look gives you the model with a layer slider, so you can scrub up through the print layer by layer and catch a raft that is not there or a first layer that is. Colour by feature type separates walls, infill and support; colour by extruder shows which tool lays down what. The print stats panel reads dimensions, layer count, estimated time and filament usage straight from the file.

It reads plain .gcode from any slicer, and Prusa's binary .bgcode format, which required implementing three separate decompression schemes: deflate, heatshrink and MeatPack. The parser is a byte scanner written from the published specification, which is why it opens hundred-megabyte files without complaint.

Works with Cura, PrusaSlicer, OrcaSlicer, Bambu Studio and anything else that emits standard G-code.

Requirements

Universal binary, so it runs on both Intel and Apple Silicon Macs.

• macOS 14 (Sonoma) or later
• Intel Mac or Apple Silicon (M1 or newer)

Installation

Download the file, unzip it, and copy it into your Applications folder. Open it once and it registers the Quick Look handler itself. Instructions are included with the download.

Apps downloaded here are signed by Apple, so you shouldn't see any Gatekeeper warnings.

Licence

What you may do: install and use the software, at no cost, on any Mac you own or control, for personal or business purposes.

What you may not do: sell, rent, lease, sublicense or otherwise charge anyone for the software; redistribute, repackage, bundle or host it for download (please point people at the official download page instead); or modify, adapt, translate, reverse-engineer, decompile or disassemble it, except to the limited extent applicable law expressly permits.

The software is licensed, not sold. All rights not expressly granted above are reserved by the copyright holder, who may offer future or paid versions under different terms.

Privacy

100% on-device. No accounts, no tracking, never connects to the internet, collects no data whatsoever.

Feedback

Please contact me with any feedback, issues, suggestions or requests!