What the tester sees on an MX Master
Logitech’s spec for the MX Master 3S lists seven buttons: left and right click, back and forward, middle click, the mode shift button behind the wheel and the gesture button under your thumb (App-Switch in Logitech’s spec), plus the thumb wheel. The MX Master 4 adds a haptic sense panel. Five of those buttons reach a web page as mouse buttons, and each has a row in the table above. The mode shift and gesture buttons are drawn dashed, because the mouse and Logi Options+ keep them to themselves, and the thumb wheel arrives as sideways scrolling. A control-by-control list follows the copy.
Testing the MagSpeed wheel
The MagSpeed wheel has a ratchet mode that clicks line by line and a free-spin mode for long pages. With SmartShift on, it moves from ratchet to free-spin by itself as you scroll faster; Logi Options+ can turn SmartShift off or change how fast it shifts, and the mode shift button switches by hand.
- In ratchet mode, roll the wheel slowly in both directions. The Up and Down counters should rise steadily and the Glitches counter should stay at 0: a glitch is a single step the wrong way in the middle of a steady scroll.
- Flick the wheel. It should switch to free-spin and send a quick burst of events in one direction.
- Roll the thumb wheel both ways. It scrolls sideways, so it counts under Left / right and lights the arrows beside it on the diagram.
If a direction stays at zero or the page jumps back while you scroll, try the stuck-wheel steps in the FAQ, then contact Logitech support.
Quiet Clicks and double clicks
The MX Master 3S and MX Master 4 have Quiet Clicks: Logitech measures 90% less click noise than on the MX Master 3. A quieter click is still a switch that wears, so give each button a long run of ordinary single clicks, around a hundred. The detector flags any press that follows the previous one on the same button by less than 80 ms, and it watches back and forward as closely as the main buttons.
The polling-rate panel has no target on this page, because Logitech doesn’t publish a rate for every model; around 125 Hz is what its specs list. That’s far from the gaming rates of the Logitech G502 or the 8K polling rate test, and it’s no fault. For any other mouse, use the standard mouse tester.
Every MX Master control and where it shows up
| Control | In the tester above |
|---|---|
| Left and right buttons | Left and Right rows, and the double-click detector |
| Main wheel click | Middle row |
| MagSpeed wheel roll | Scroll wheel panel: Up and Down |
| Thumb wheel | Scroll wheel panel: Left / right |
| Back and forward buttons | Back and Forward rows (on a Mac, with Logi Options+ installed) |
| Mode shift button (on top) | Nothing by default: it switches the wheel between ratchet and free-spin |
| Gesture button | Doesn’t light up: Logi Options+ turns it into gestures |
| Haptic sense panel (MX Master 4) | Doesn’t light up: Logi Options+ opens the Actions Ring |