Mechanical keyboard switches, from scratch

A switch is the little spring-loaded part under each key on a mechanical keyboard. There is one under every key, and they decide how the whole board feels and sounds: smooth, bumpy, clicky, deep, or sharp. They are also the easiest part to change later, since most modern boards let you pull switches out and pop new ones in.

What is inside a switch

Every standard switch has the same handful of parts: a top and bottom housing, a stem that moves up and down, a spring, and two metal contacts. When you press a key, the stem pushes down and the contacts touch, which registers the keypress. Let go, and the spring pushes the stem back up.

Stem: the moving part. Its shape decides whether the switch is linear, tactile, or clicky.
Spring: sets how heavy the key feels to press.
Housing: the outer shell. The plastic it is made from changes the sound a little.
Contacts: the metal pieces that touch to register the press.

The three types

Linear

Smooth all the way down, with no bump and no click. Pressing a linear switch feels like pressing a smooth button. They are fast and quiet, which is why a lot of gamers like them.

Great for gaming and fast typing.
The sound is all in the bottom-out, which people describe with words like creamy or thocky.
Examples: Cherry MX Red (light), Gateron Yellow (smooth and a popular budget pick), Gateron Oil King (creamy, lubed at the factory).

Tactile

There is a small bump partway down that you can feel as the key registers. The bump tells your finger the press worked, so you do not have to press all the way down. Many people find this comfortable for typing.

Great for lots of typing, because the bump gives you something to feel.
Examples: Cherry MX Brown (mild bump), Gateron Brown, Boba U4T (deep and thocky), Holy Panda (sharp and loud).

Clicky

A bump plus a loud click sound on every press. Satisfying to some people, annoying to everyone nearby.

Fun at a private desk, but a bad idea on calls or in a shared room.
Examples: Cherry MX Blue (mild), Kailh Box White (sharp and popular), Kailh Box Jade (heavier and crisp).

Spring weight: how heavy the key feels

Spring weight is how much force it takes to press a key, measured in grams. Lighter keys are faster but easier to press by accident; heavier keys feel more deliberate. Most people are happy in the medium range.

Weight	Feel	Good for
35 to 45 g	Very light, easy to press by accident	Fast typing, light-touch gaming
45 to 55 g	Medium-light, the most common range	An easy all-rounder
55 to 65 g	Medium, the classic feel	The default for most enthusiast switches
65 to 75 g	Heavier and more deliberate	Typists who want fewer accidental presses
75 g and up	Very heavy	A niche taste

Tip

Spring weight is the easiest thing to change. If you like a switch but want it a bit heavier or lighter, you can swap just the springs instead of buying new switches.

Travel and actuation, in plain terms

Actuation point: How far down you press before the key registers. Most switches register at about 2 mm. Speed switches register sooner, around 1 to 1.2 mm.
Total travel: How far the key can go down in total. Usually about 4 mm. Low-profile switches are shorter, around 3 to 3.5 mm.
Adjustable actuation: Some switches (Wooting and Razer analog boards) let you choose how far down the key registers, set in software.

What lubing does

Lubing means adding a thin layer of grease inside the switch to make it smoother and quieter. You do not have to do this yourself. Most modern switches come pre-lubed from the factory and already feel great.

Note

Pre-lubed switches (Akko, Gateron Oil King, and many others) are so good now that you can buy an excellent keyboard without ever modding it. Hand-lubing is a hobby, not a requirement.

Optical and magnetic switches

Optical: Uses a beam of light instead of metal contacts to register the press. Slightly faster and nothing metal to wear out. Examples: Razer Optical, Gateron Lekker (Wooting).
Magnetic (Hall-effect): Uses a magnet to measure exactly how far the key is pressed. This lets you set the actuation depth in software, get instant repeat presses, and even use keys as analog controls (like a steering or throttle input). It is the most exciting recent change in gaming keyboards.

Picking your first switch

Buy a switch tester (about $10 to $20 with several switches). Press each one a few times and notice which you like.
Choose linear, tactile, or clicky based on your space (no clicky in a shared room) and your use (lean tactile if you type a lot).
Pick a weight around 45 to 60 g to start. Too light causes typos, too heavy tires your fingers.
If you can, get a board with hot-swap sockets, so your first switch does not have to be your last. Changing later costs a little, not a whole new keyboard.