GCodexWhat is G0?
G0 commands the machine to move to a target position at maximum speed. It is a non-cutting travel move — never use G0 while the spindle or extruder is active over a workpiece.
Syntax
G0 [X] [Y] [Z] [A] [F]
Parameters
| Parameter | Description |
|---|---|
| X | Target X-axis coordinate (mm or inches) |
| Y | Target Y-axis coordinate |
| Z | Target Z-axis coordinate |
| A | Target A rotary axis (degrees) — 4/5-axis only |
| F | Feed rate override for this move (optional, usually ignored in rapid) |
Examples
G0 X100 Y50↑ Rapid move to X=100, Y=50 (Z unchanged)
G0 Z5↑ Lift to safe height of 5mm (retract before travel)
G0 X0 Y0 Z50↑ Rapid to machine origin at safe Z height
Important Notes
- G0 moves at the machine's maximum configured speed — typically much faster than G1 feed moves.
- On most controllers G0 is modal — stays active until G1, G2, or G3 overrides it.
- All axes move simultaneously, reaching the target together (coordinated motion).
- In 3D printing G-Code, G0 represents travel moves between extrusion paths.
- Never use G0 to plunge into a workpiece — always use G1 with a controlled feed rate.
Common Mistakes
- ❌ Using G0 to enter the cut — rapid plunges break tools and damage workpieces.
- ❌ Not retracting Z before a G0 lateral move — tool drags across the work surface.
- ❌ Assuming G0 follows a straight path — on some machines, non-cutting moves are interpolated differently.
Frequently Asked Questions
Q: What is the difference between G0 and G1?
G0 is rapid positioning at maximum machine speed — used for travel moves only. G1 is linear interpolation at a controlled feed rate — used for cutting or extrusion moves. G0 prioritizes speed; G1 prioritizes precision and controlled material engagement.
Q: Does G0 move in a straight line?
G0 typically moves all programmed axes simultaneously, which produces a straight line in 3D space. However, the path is not guaranteed to be perfectly linear on all controllers — never assume G0 takes a specific path when near the workpiece.
Q: What speed does G0 use?
G0 uses the machine's maximum configured rapid speed — set in the controller's parameter file or in Marlin's MAX_FEEDRATE settings. You cannot reliably slow G0 with an F word on most machines.