Ultramini keyboards in 40% format

40% (ultramini)

— a radically compact layout with approximately 40–50 keys without a number row, arrow keys, and function keys: everything is accessed through Fn layers, key combinations, and macros, often featuring an ortholinear matrix. Due to the minimal width, the mouse is closer to the center, reducing hand spread and freeing up desk space, which is appreciated by mobile users and minimalists. Compared to 60% and 65% formats, the 40% format requires more serious adaptation and thoughtful firmware (QMK/VIA, home-row mods, tap-dance), and selecting keycaps is more challenging due to non-standard sizes. Its strong suit is portability and speed after acclimation; its weakness is dependency on layers and inconvenience with frequent number input and arrow navigation. The 40% format is practical for travel, working on a laptop with a docking station, text editing with hotkeys, and streaming, while the need for numbers is usually met with an external NumPad.