Provides core functionality and UI integration for GRBL based engravers and CNC machines


This plugin was inspired by mic159’s Grbl Support plugin ( His plugin gets you 90% of the way there for adding Grbl support to Octoprint but had a couple limitations and lacked some bells and whistles from a UI and configuration perspective.

Better Grbl Support utilizes mic159’s gcode receiver parser (with significant modifications) and does much, much more:

  • Replaces Octoprint’s Control tab with its own Grbl Control tab
  • Execute bounding box (framing) routines based on origin location and supplied dimensions
  • Computes selected file dimensions and pre-populates framing length/width fields
  • Converts Grbl error and alarm #s to meaningful descriptions
  • Grbl Homing support
  • Modify all Grbl ($$) settings via Better Grbl Support settings
  • Backup and restore Grbl ($$) settings
  • Click on the webcam image to enlarge it to its native resolution
  • Visually updates State / X / Y / Speed / Power dynamically, even while printing!
  • Weak Laser Toggle, Sleep, Reset, and Unlock buttons in the Grbl Control tab
  • Rewrites Octoprint’s annoying hardcoded M115 (Hello) queries as M5 requests
  • Rewrites M105 (temperature updates) as Grbl status updates
  • Suppresses M110 (reset line #) requests
  • Rewrites M400 (Finish moves) using Grbl Dwell
  • Rewrites M114 (current position) using Grbl Positioning
  • Implements M999 for reseting Grbl (^X)
  • Hides the Octoprint Control, Temperature and GCode Viewer tabs
  • Optionally adds Laser Commands and State sections to the Control tab
  • Suppresses status update reporting during GCODE streaming
  • No need to ignore firmware errors or track down other Octoprint nuance settings
  • Automatically disables Model Size Detection
  • Automatically disables sending checksums
  • Automatically disables the Printer Safety Check plugin
  • Most configuration options are accessible via Plugin Settings


Install via the bundled Plugin Manager or manually using this URL:


There are some meaningful caveats regarding the installation and configuration of this plugin. If you use it in a multi-printer / profile environment it will very likely cause problems for your other profiles as it makes GLOBAL configuration changes behind the scenes. A future version may resolve this, but understand that currently multi-profile installations are not currently supported.

Furthermore, a number of global configuration changes are made blindly and I have no way of reverting these changes. Be prepared to manually edit your config.yaml and/or manually revert global settings if you uninstall / disable this plugin to restore your Octoprint installation to its prior state.

Pay special attention to the following config.yaml configuration parameters:

  • appearance / components / temperature tab
  • controls (any / all customizations made to it)
  • feature / temperatureGraph
  • feature / gcodeVisualizer
  • feature / modelSizeDetection
  • serial / neverSendChecksum
  • serial / checksumRequiringCommands
  • serial / helloCommand
  • plugins / _disabled / printer_safety_check
  • appearance / components / disabled / tab


Main UI
Plugin Settings