Choc vs MX vs Topre

Choc, MX and Topre are three different switch families, and their keycaps don't swap between them. Each has a different stem (the post under the cap that the keycap clips onto), so a cap cut for one simply won't fit another. This guide covers the differences and how to check.

MX is the standard mechanical switch: a cross-shaped (+) stem on a tall body, and what most mechanical keyboards and keycaps are built around. Choc is Kailh's low-profile switch, a shorter body with two flat rectangular stems instead of a cross, which is why Choc boards sit so much lower. Topre is different again: an electrostatic-capacitive switch with a rubber dome under a round, circular slider, prized for its smooth, cushioned press. Each stem shape is a dead giveaway once you've seen it.

The fastest check is to pull one keycap and look at the stem. A cross in the middle means MX. Two small rectangles means Choc. A round slider in a circular housing means Topre. If you'd rather not pull a cap, check your board or switch model: the manufacturer's spec names the switch family. A keycap puller makes this painless; grab one here if you don't have one.

"Low profile" describes the switch height, not the family. Some MX switches are themselves low profile, shorter than a standard MX, and they still take MX-stem keycaps. The catch is clearance: a tall, deep keycap can foul the switch housing, because the cap's internal walls reach further down than a low MX switch leaves room for. Cherry profile is a common culprit. To avoid the interference, pair low-profile MX switches with a profile built for that clearance: PFF or LPF. Both clear the common low profile MX switches, so the choice is really about material: PFF is opaque PBT with dye-sub legends, LPF is ABS made for shine-through on a backlit board.

The stem isn't the only thing that differs: the two families are usually spaced differently too. Choc boards tend to use a narrower pitch (the centre-to-centre distance between keys), with a standard of 18 × 17 mm, against MX's usual 19.05 × 19.05 mm. Keycaps are sized to match their pitch, so caps cut for one spacing on a board built for the other can leave you either unable to mount them at all, or with uneven, inconsistent gaps around each key. When you're picking a Choc set, check it's made for Choc spacing, not just a Choc stem.

Once you know the family, the set follows. MX → KLP Lamé, PFF, LPF, DSA Way or SLK. Choc → MBK, KLP Lamé or MNT Pocket. Topre → URSA. For how the profiles themselves differ in height and sculpt, see Compare keycap profiles. When you're ready, the full catalog filters by switch type so you only see what fits.