GRBL controller application with G-Code visualizer written in Qt.
C++ Other
Latest commit 5aeeec3 Jan 8, 2017 @Denvi Selected line marker fix
(cherry picked from commit f90d97a)


GRBL controller application with G-Code visualizer written in Qt.

Supported functions:

  • Controlling GRBL-based cnc-machine via console commands, buttons on form, numpad.
  • Monitoring cnc-machine state.
  • Loading, editing, saving and sending of G-code files to cnc-machine.
  • Visualizing G-code files.

System requirements:

  • Windows/Linux x86
  • CPU with SSE2 instruction set support
  • Graphics card with OpenGL 2.0 support
  • 120 MB free storage space

Version 1.1 release:

  • Reworked for GRBL v1.1 firmware


Version 1.0 release:

  • Added "Grayscale segments"-option and "Raster"-mode to visualize laser jobs.
  • Added "User commands"-panel.
  • "Send from current line" feature added.
  • G-code program errors handling.
  • Significantly improved performance of:
    • File loading.
    • G-code program modification by heightmap.
    • "Autoscroll"-feature.
  • Programs with about 5 million lines can be loaded now.


Build requirements:

Qt 5.4.2 with MinGW/GCC compiler

Previous versions:






Version 0.9 release:

  • "Restore origin" function has "move tool in plane/space" setting now.
  • "Safe position" function can be customized with command list.
  • Visualizer works with OpenGL/Angle/Software renderer.
  • Some bugs fixed.

Version 0.7 release:

  • Drag & Drop mechanism support added. You can drop files & plain text to main program window to open them.
  • "Abort" button added. File transfer can be interrupted without loss of work coordinates offsets now.
  • M2, M30, M18, M19 commands support added.
  • French translation added.
  • Some bugs fixed.

Version 0.6 release:

  • Improved visualizer performance.
  • Some appearance settings added.

Version 0.5 release:

  • Toolpath highlighting on g-code program table selection.


Version 0.4 release:

G-code modification with heightmap.

Original file: screenshot

Heightmap: screenshot

Bicubic interpolation: screenshot

Modified file: screenshot

Version 0.3 release:

  • Recent files & commands lists added.
  • Custom Z-probe commands supported now.
  • Imperial units of GRBL reports support added.
  • Main form compacted.

Visualizer only view: screenshot

Table only view: screenshot

Live G-code editing: screenshot

Version 0.2 release:

  • Jog/spindle control with numpad added:
  • Feed override function added.
  • "Spindle", "Feed", "Jog" groupboxes collapsible now.
  • Visualizer works in "Check mode" now.
  • Visualizer Z-buffer option added.
  • Some bugs fixed.


Support the "grblControl" project. If you'd like to donate, all proceeds will be used to help fund supporting hardware and testing equipment. Thank you.

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