Logitech MX Master 4 Leak Reveals New Design and Extra Thumb Button
Logitech’s popular MX Master series has long been the go-to mouse for professionals and productivity-focused users, and now it looks like a new generation is on the way. Leaked images from the European Union Intellectual Property Office suggest the MX Master 4 is just around the corner, showing off a familiar design with a few meaningful upgrades—including a new thumb button.
The unannounced model was first spotted in regulator filings by Notebook Check. Though the product name isn’t explicitly mentioned, the design unmistakably resembles an evolution of the MX Master 3S. Logitech’s refined aesthetics are on full display: the separation between the main click buttons and the body is cleaner, the scroll wheel mode-switch appears more accessible, and the status LED has been moved from the side to the top for better visibility.
The biggest change is to the thumb area. The gesture button—previously placed at the bottom edge—has been moved closer to the main thumb buttons, and now there’s a third thumb button nestled beside them. While its function hasn’t been confirmed, speculation points to a dedicated “AI Prompt Builder” shortcut, in line with Logitech’s push into AI-assisted workflows.
Under the hood, we could see sensor improvements too. The current MX Master 3S features an 8000 DPI sensor, but given the trends in high-performance mice—even for non-gamers—Logitech may push that number higher.
Pricing is likely to remain around the $120 mark, where the MX Master 3S currently sits, particularly after tariff-related price adjustments in recent years. As for the release date, Logitech hasn’t officially confirmed anything, but the polished look of these regulatory images suggests a launch is likely before fall, possibly to coincide with the back-to-school season.
