Keychron K3 Max SE brings QMK customization to ultra-slim 75% board

Keychron pushed QMK customization into a thinner, more travel-ready frame with the K3 Max SE, a $104.99 75% low-profile board that keeps 2.4 GHz, Bluetooth 5.2 and wired USB-C in play. The pitch is simple but pointed: give laptop-style portability without stripping out the remapping and layer support that make a board feel truly ownable.

That balance matters because the K3 Max SE lands in a part of the market where every compromise is visible on the desk. Keychron built it as an ultra-slim wireless custom mechanical keyboard with hot-swappable low-profile MX switch support, acoustic foam and LSA low-profile spherical-angled keycaps. The company says buyers can configure it through Keychron Launcher with QMK and VIA support, which means the board is not locked into a fixed factory layout. For a 75% board, that is the difference between a convenient compact board and one that can actually be tuned for day-to-day use, from media keys to deeper custom layers.

The K3 Max SE also arrives as part of a growing low-profile lineup that is no longer treating slim boards as a side experiment. Keychron’s broader collection now spans K3 Max, K3 Ultra, K3 HE, K5 Max, K15 Max and K17 Max models, showing how segmented this corner of the hobby has become. The K3 Max family has already existed as a 75% low-profile QMK/VIA line with some configurations listed lower than the SE, so this new model reads less like a reinvention and more like a cleaner entry point into the same idea.

That positioning becomes clearer next to the K3 Ultra 8K, which Keychron lists at $109.99. The Ultra moves to ZMK firmware and adds 8K wireless polling plus up to 550 hours of battery life, turning the family into a split between software-first customization and spec-sheet muscle. Against that backdrop, the K3 Max SE looks like the practical middle path: cheaper than the Ultra, still wireless, still low-profile, and still built around the enthusiast expectation that the keyboard should adapt to the user, not the other way around.

TechPowerUp and XiaomiToday both dated coverage of the K3 Max SE to April 10, 2026, and both framed it as a simpler sibling inside Keychron’s expanding slim-board lineup. That is the real story here. Low-profile boards are no longer just a thinner detour from mechanical keyboards. With the K3 Max SE, Keychron is betting that portability and hobby-grade control can share the same case.