60%, 65%, 75%, TKL, full-size — the names read like a settled taxonomy, but each cut trades away a specific cluster of keys for a specific amount of desk space. Here's what a reader actually keeps and gives up at each size, and how a firmware layer changes the math.
Two boards can look nearly identical in a listing photo and still take entirely different keycap sets. Here's how to read Enter key shape, bottom-row widths, and spec-sheet shorthand before ordering — not after a set arrives that doesn't fit.
Every custom-keyboard buyer's guide since the mid-2010s opens with the same four-term vocabulary — 60%, 65%, 75%, TKL — as though it always existed. It didn't. One open-source PCB out of a geekhack thread is most of the reason that taxonomy exists at all.
Alice mounts had a clear moment between 2021 and 2023 — the splayed alphas, the angled bar, the promise of a typing posture that didn't twist your wrists. The thock trends snapshot for 2026-W19 pegs Alice movement at -18 and trending down. The layout still has loyal users, but the curve has bent.
Two years ago a custom-board recommendation defaulted to 65% with a polite note about 75% as the next step up. The KBD75 v3's staying power as a default recommendation, the QK75, and a crowded mid-tier have flipped that order. 75% is now the layout customs reach for first.
A split board is two keyboards that happen to share a keymap. Most builders still buy parts for it like it's one — matching switches, ordering a single sculpted keycap set, and never touching the left half's tuning differently from the right's.