Topre & EC explained

Most mechanical keyboards run on MX switches, and Choc has become a fixture on low-profile ergo boards. Topre is the quiet third option. It works on a different principle altogether, takes its own keycaps, and answers to two names: Topre, the brand, and EC, the technical term. This guide explains the difference, shows you what a Topre switch is actually made of, and points you to caps and parts that fit.

"Topre" isn't really a switch type, it's a company. Topre Corporation is the Japanese manufacturer behind the original electrostatic-capacitive keyboards, and the brand name stuck to the switch the way brand names often do. Strictly speaking the technology is EC: electrostatic capacitive. Instead of two metal contacts touching to register a press, an EC switch reads the change in capacitance as a spring compresses under the keycap. Nothing metal has to make contact, which gives Topre its signature smooth, cushioned keystroke, quite unlike the click of MX or the snap of Choc. So when someone says "Topre," they usually mean "an EC board," the same way people reach for a brand name when they mean the whole category.

If the technology is the same, why two words? Topre refers to switches actually made by Topre Corporation, the ones in boards like Realforce and the HHKB. EC is the broader, vendor-neutral term for any switch built on the same dome-and-slider, capacitive-sensing design, including the growing number made by other manufacturers and the custom scene. In practice they feel and behave alike, and the community uses EC-compatible as the catch-all for caps, domes and parts that fit the whole family rather than one brand. When we call a keycap EC-compatible, that's the point: it fits the slider, whether your board says Topre on it or not.

You've probably come across a few of these without clocking that they're EC under the caps:

• HHKB (Happy Hacking Keyboard): the compact 60% cult classic, a long-standing favourite among programmers.
• Realforce: Topre's own full-size and TKL line, known for its variable and uniform weightings.
• Leopold FC660C / FC980C: Topre versions of popular compact layouts. The models whose names end in C were the EC ones, though Leopold has since stopped making them.
• NIZ: electro-capacitive boards, often wireless, at a more accessible price.

If your board is one of these, or its spec sheet mentions Topre, EC or "capacitive," you're in the right place.

Realforce packaging once described it as the "good feeling of oneness with the cup rubber," and that line gets closer than most. There's something about an EC keystroke that fans can't stop talking about, yet can't quite put into words. The dome gives a deep, cushioned press that builds and releases smoothly, with none of the hard bottom-out you get from a typical MX switch. It's so unlike anything in the MX world, even with the countless MX options around today, that it genuinely has to be felt rather than explained. That singular feel is why Topre owners tend to stay Topre owners, rarely drifting back to MX, and why the custom EC scene keeps growing year on year as more people get a taste of it.

A Topre switch is a small stack of parts rather than one sealed unit. From the top down: the keycap sits on a slider that travels inside a housing moulded into the board's top plate. Under the slider sits a rubber dome, which supplies the tactile force and springs the key back up. Inside that dome is a conical coil spring resting just above the PCB. As you press, the spring compresses toward the board and changes the capacitance the PCB reads, and that change is the keypress. It's why an EC keystroke feels so different: you're feeling a rubber dome, not a metal leaf, and the board is sensing a field rather than a contact.

If you want to go deeper, the original mechanism is documented in Topre's US patent US4584444A, which expired back in 2004. One practical upshot of the dome doing the work: you can change how a board feels just by swapping the dome. We make EC domes that drop into any existing Topre or EC keyboard, for a lighter, more uniform press without touching the rest of the switch.

If you're building an EC board up from parts, reviving one with a dead row or a flaky connection, or modding toward a different layout, an EC replacement PCB is what you're after. We stock replacement PCBs for the HHKB and for some Realforce and Leopold boards. EC boards vary, so check a PCB against your specific keyboard before ordering. Browse our Topre and EC replacement PCBs to find the right fit for your board.

Here's the gap we set out to fill. For all the loyalty EC inspires, the keycap options have always been thin. Before URSA there was no genuinely high-quality set made for Topre and EC boards, and no manufacturer had ever produced doubleshot caps for them at all: EC owners were left with their stock caps or with compromises. URSA changes that. An enormous amount of care went into getting it right, from the slider fit to the crisp doubleshot legends, and it's the product that puts FK at the front of this small but serious corner of the hobby. We've documented the whole process behind URSA, from first prototypes to production, in our URSA development updates.