How to Directly Preview G-Code & BG-Code Files in Mac Finder? (No Slicers Required)

For 3D printing enthusiasts, makers, and CNC machinists, G-Code and the latest binary BG-Code are essential daily formats. Each time you slice a model in software like Bambu Studio, PrusaSlicer, OrcaSlicer, or Cura, you export one or more G-Code files to print or machine.

However, when organizing or checking these files in folders, macOS presents a frustrating bottleneck: Finder cannot natively display G-Code/BG-Code files, leaving you with a sea of generic, identical blank document icons.

To verify which 3D model a G-Code file corresponds to, you traditionally have to wait for heavy slicer software to load. Having to launch a massive application just to take a quick peek at your files is extremely time-consuming and wastes system memory.

💡 Tip: To preview G-Code/BG-Code files and generate thumbnails directly in Finder without launching slicers, the easiest and most native solution is to install a specialized macOS QuickLook extension, such as GCodePreview.

The New Solution: 3D Toolpaths Independently Rendered by GCodePreview

Designed specifically for macOS, GCodePreview integrates seamlessly into the native QuickLook and Thumbnail extension APIs of Finder. It provides a massive efficiency upgrade over traditional workflows:

  • Automatic Finder Thumbnails: G-Code/BG-Code file icons in your folders are automatically replaced with detailed 3D toolpath visualizations. No more guessing.
  • Instant Quick Look (Spacebar): Select a file and hit Spacebar to instantly view high-resolution 3D toolpaths in Finder, responding within milliseconds.
  • 100% Local Parsing (Independent of Embedded Images):

    Many basic preview extensions can only extract embedded PNG thumbnails (Base64) saved by slicers. If you disable thumbnail output in your slicer settings, or use legacy slicers that don't support it, those extensions fail to show anything.

    GCodePreview features a built-in high-performance G-Code path parser. It reads the actual nozzle movements (like G0, G1) and reconstructs high-fidelity 3D toolpaths locally on your Mac. Even if your G-Code has absolutely zero embedded images, GCodePreview renders it perfectly.

If thumbnails do not refresh immediately after installation, it is usually due to macOS system cache lag. You can refer to our Troubleshooting Guide to resolve it in seconds.

Comparison of G-Code Preview Methods

Here is a head-to-head comparison of GCodePreview against traditional viewing workflows to highlight the efficiency gains:

Preview Method Finder Thumbnails Startup Time No-Thumbnail Support Memory Overhead Data Privacy (Offline)
GCodePreview Supported (Auto-generated) < 1 second (Native) Perfect Support (Parses paths) Negligible (No daemon) 100% Local (Private)
Traditional Slicers (e.g., Bambu Studio) Not Supported 5 - 15 seconds Supported (Fully loads file) Very High (Heavy 3D engine) 100% Local
Online 3D Viewers Not Supported Depends on upload speed Supported (Requires upload) Medium Low (Upload privacy risks)
Optimize Your Mac Maker Workflow Today

Bring native G-Code and binary BG-Code thumbnails and QuickLook previews to macOS Finder. Auto-parse paths, view files instantly.

Download on the App Store

Frequently Asked Questions (FAQ)

Does GCodePreview require G-Code files to contain thumbnails exported by slicers?
Absolutely not. GCodePreview features a proprietary 3D path parsing engine. Even if your G-Code files don't have embedded thumbnails or your legacy slicers don't support exporting them, it reads the toolpath movements and renders high-precision 3D previews locally.
Which file formats are supported besides standard .gcode?
In addition to standard plain-text formats like .gcode, .g, and .gco, it fully supports the latest binary-encoded .bgcode (BG-Code) format from PrusaSlicer, parsing and rendering them within milliseconds.
Why do my G-Code files still display generic document icons after installation?
This is usually caused by delayed macOS Finder cache updates. You can check our Troubleshooting Guide for quick steps to reset the system QuickLook cache or simply restart Finder to resolve the issue.