What’s actually under the keycap

Mechanical means each key has its own self-contained switch: a housing, a spring, and metal contacts. Press the key, the stem travels, the contacts close at the actuation point (~2mm down on most switches), and the spring pushes the cap back up. The feel is defined by that mechanism — consistent from the first press to the fifty-millionth.

Membrane means keys sit on rubber domes over a printed circuit sheet. Pressing collapses the dome, which pushes a conductive pad onto the circuit. The dome is both the spring and the contact. It works, it’s cheap to make, and it’s why most bundled keyboards feel the way they do.

Scissor switches — what laptops use — are a hybrid worth naming separately: a membrane dome underneath, but a plastic scissor mechanism on top that stabilizes the cap so it travels straight down over a very short distance. That’s why a decent laptop keyboard can feel crisp despite being membrane-based.

What actually differs in practice

• Consistency. A mechanical switch actuates at a defined point with a defined force, key after key, year after year. A membrane dome’s actuation point is vaguer and drifts as the rubber ages.
• Feel options. Membrane gives you one feel: dome collapse. Mechanical gives you a spectrum — linear, tactile, clicky — plus spring weights and aftermarket keycaps that change how the whole board types.
• Sound. Domes thud softly. Mechanical switches have a sharper bottom-out, plus the click on clicky variants. Whether that’s satisfying or infuriating depends on your coworkers.
• Durability. Metal springs outlast rubber domes by roughly an order of magnitude — the reason a 30-year-old Model M still works and why gaming boards advertise 50M+ press ratings.
• Repairability. Many mechanical boards have individually replaceable switches (hot-swap sockets, or soldered switches you can desolder). A dead dome usually means a dead keyboard — you can’t replace one dome on a membrane sheet.
• Price and thickness. Membrane wins both. That’s why it owns the sub-$30 market and why ultra-thin keyboards exist at all.

A simple way to compare for yourself

If you have both kinds of board handy, run the keyboard tester on each and press the same row of keys slowly. On the membrane board you’ll notice the actuation point feeling soft and slightly different key to key; on the mechanical board each key registers with the same clean press. Neither is wrong — they just wear and feel differently.

What to buy, honestly

If you type all day and the board is your tool, a mid-range mechanical board pays for itself in durability alone. If you need cheap, thin, spill-friendly or silent, membrane and scissor designs are genuinely good at those things — the mistake is buying a $15 membrane board expecting mechanical longevity, or a $150 mechanical board expecting a promised typing-speed upgrade that won’t materialize.

Frequently asked questions

How can I tell if my keyboard is mechanical or membrane?

Pull one keycap (a credit-card edge works on most boards). Underneath, a mechanical switch looks like a small cross-shaped stem on a self-contained plastic housing; a membrane board shows a rubber dome or a bare rubber sheet. Full-travel desktop keyboards under ~$30 are almost always membrane; laptop keyboards are usually scissor switches over a membrane — a third category, not really either.

Do mechanical keyboards make you type faster?

No solid evidence says so. Mechanical switches give more consistent tactile feedback, which many people find less fatiguing and more satisfying — comfort can indirectly help speed over long sessions. But measured typing-speed studies find differences within normal person-to-person variation. Buy one for feel and durability, not for a promised WPM bump.

What do 'linear', 'tactile' and 'clicky' mean?

The three switch feel families. Linear (Cherry Red-style) travels smoothly with no bump. Tactile (Brown-style) has a small bump at the actuation point you can feel but not hear much. Clicky (Blue-style) adds an audible click to the bump. Actuation force — how hard you press — is a separate axis, typically 45–60g.

Are membrane keyboards quieter?

Generally yes — a rubber dome bottoming out is duller and lower-pitched than a hard plastic switch bottoming out, and there's no click mechanism. But mechanical boards can be quieted (O-rings, silent-switch variants, lubricant) and a heavy-handed typist makes any board loud.

Why do membrane keys feel mushy over time?

The rubber dome is the spring. Rubber fatigues and permanently deforms with age, so the dome's snap softens — that's the growing mushiness and why old membrane boards feel dead. A mechanical switch uses a metal spring that barely fatigues, which is the main reason mechanical boards are rated for 50–100 million presses versus ~5–10 million for domes.