Gantry: GRBL CNC Controller

Gantry turns your phone or tablet into a wireless controller and monitor for your GRBL-based CNC router. Jog the machine, stream G-code, watch the cut in 3D, and run a job from across the workshop — connected straight to your controller or over Wi-Fi.

TWO WAYS TO CONNECT
• Direct — plug your phone into the controller with a USB-OTG cable, or pair over Bluetooth (classic or BLE). No PC, no network — your phone is the pendant and the sender.
• Networked — run the free Gantry server on the PC wired to your machine and connect over Wi-Fi to control and monitor from anywhere in the shop.
• Simulator — a built-in GRBL simulator lets you try every feature with no hardware attached.

WHAT YOU CAN DO
• Live DRO — machine and work coordinates (X/Y/Z), feed, spindle and controller state in real time.
• Jog — on-screen XY pad and Z with selectable step and feed.
• Homing & zeroing — home all or per-axis, set work zero, go to work or machine zero.
• Stream G-code — load a file, watch progress, current line and time remaining, with start / pause / resume / stop and emergency-stop.
• 3D toolpath viewer — pan, zoom and rotate; rapids and cuts colour-coded; the tool head moves as the job runs.
• Feed & spindle overrides — adjust on the fly.
• Console and event log, machine profiles, GRBL settings with backups.
• Themeable, movable dashboard — drag, resize and show/hide panels; your layout is remembered.

DON'T LOSE YOUR JOB
• Run-from-line recovery — if a job stops (power blip, dropped link), resume from any line with a safe re-entry.
• Auto-reconnect — if the controller link drops, Gantry retries and reconnects on its own.
• Keep-awake — the screen won't sleep mid-job.
• Pre-flight checks — catch out-of-bounds moves and rapids into the stock before you press start.
• Plain-English alarm decoder — every GRBL alarm explained, with the fix. Always free.

GO FURTHER (optional add-on packs)
• Probing pack — Z touch-plate, X/Y edge, corner, hole-centre and skew, plus auto-levelling height maps.
• M6 tool-change wizard — guided pause, tool swap and re-probe.
• Batch mode — run the same job across a grid of parts with per-part progress.
• Gamepad jog — jog with a connected game controller.
• grblHAL network + SD — connect over the network and run jobs from the controller's SD card.
• Image & vector to G-code — turn artwork into engraving or 2.5D relief toolpaths, including V-bit.
• Feeds & speeds calculator, custom material library, extra themes and unlimited profiles.

WORKS WITH
GRBL 1.1, grblHAL and FluidNC controllers — the standard GRBL path.

FREE TO START
Core control, monitoring, the 3D viewer, the simulator and the alarm decoder are free, with no account. Advanced features are available as one-time in-app purchases — buy only the packs you want, or the All Access bundle. No subscription.

PRIVACY
No account. No ads. No tracking. The app only talks to the controller or server you connect it to. See our privacy policy for details.

SAFETY
A CNC machine is powerful and can cause injury. When connected directly, Gantry drives your GRBL controller — always follow safe machining practice: keep clear of the machine, know where your emergency stop is, and never leave a running job unattended.