Logitech is apparently planning to refresh its MX Master series with the MX Master 4, which appears to feature a number of changes compared to the MX Master 3S, although there has so far been no confirmation that the MX Master will solve the most common complaint about the MX Master 3S—the low 125 Hz polling rate. The most recent leak of the MX Master 4 comes directly from Logitech, with a mention of the upcoming productivity mouse on the brand's "Best Mice for Students" page (and a few other similar round-ups) confirming other recent leaks that suggested the updated design was in development. Unfortunately the original pages have since been edited to remove the mention of the MX Master 4, but there are screenshots on Reddit and Caschy's Blog.

More detailed leaks showed up on the r/Logitech subreddit recently, replete with high-resolution product images of the MX Master 4. Compared to the MX Master 3S that came before it, the MX Master 4 seems to mostly have the same shape, with a few tweaks to the design that should make it easier to use. For starters, the gesture button on the thumb shelf is now highlighted with a ring of small white dots, and there is an extra thumb button on the left side of the mouse, in front of the back and forward buttons. If the leaks are true, this would bring the total number of buttons to eight, including middle click and the scroll wheel unlock button. The MX Master 4 so far also looks to feature the same magnetic scroll wheel and thumb scroll functionality—both of which have earned it a reputation among productivity users. The biggest questions that still remain about the MX Master 4, though, are regarding the sensor, weight, and polling rate, since there are now mice from brands like Ugreen and Keychron that offer similar ergonomics and free-scroll functionality in lighter shells with gaming-grade sensors and up to 8 kHz polling.