Key-input mechanisms are disclosed. An example mechanism includes an arced, resilient keycap, the arc of the keycap having a first central arc angle when un-pressed. The keycap is configured to, when pressed, deform so as to have a second central arc angle, the first central arc angle being greater than the second central arc angle. The keycap is further configured to, when released after being pressed, return to its un-pressed shape having the first central arc angle. The key input mechanism further includes a switch disposed under the keycap. The switch is configured to, when the keycap is pressed, electrically couple two or more circuit traces to indicate a keystroke for the key input mechanism. The switch is further configured to, when the keycap is released, electrically decouple the two or more circuit traces to indicate that the keystroke for the key input mechanism is complete.