When shopping for a high-end gaming keyboard, you will eventually have to choose between traditional mechanical switches and the newer “optical” switches. While brands like Razer and Corsair have their own proprietary optical tech, Kailh is the leading manufacturer of optical switches for the custom and budget keyboard market.
Kailh optical switches use an infrared light beam instead of physical metal contacts to register a keystroke. Because there is no metal-on-metal friction, they completely eliminate “debounce delay,” making them objectively faster and more durable for competitive gaming.
If you are wondering if an optical keyboard is worth the upgrade, here is everything you need to know about how Kailh optical switches work and why they are dominating the esports scene.
For the full picture on layouts, switches, and mods, see our complete mechanical keyboard guide.
You might also want to check out our guides on Kailh Blue Switches Review: Are They Better Than Cherry? and Best Budget Linear Switch.
How Do Kailh Optical Switches Work?
To understand optical switches, you first need to understand how a standard mechanical switch works.
In a traditional switch (like a Cherry MX Red), pressing the key pushes a plastic stem down until two copper metal leaves touch each other. When the metal touches, the electrical circuit is completed, and the computer registers the keystroke.
Kailh Optical Switches are completely different. There are no metal leaves inside the switch. Instead, a continuous beam of infrared light shines across the circuit board (PCB) directly underneath the switch. When you press the key down, the plastic stem physically blocks or breaks that beam of light. The exact millisecond the light is broken, the keyboard sends the signal to your PC.
(Want to learn more about standard switch mechanics? Read our Ultimate Mechanical Keyboard Switches Guide).
The 3 Major Benefits of Optical Switches
1. Zero Debounce Delay (Maximum Speed)
When two pieces of metal touch in a traditional switch, they vibrate (or “bounce”) for a few milliseconds before settling. To prevent the keyboard from registering this vibration as multiple keypresses, the keyboard software enforces a “debounce delay,” forcing the computer to wait a few milliseconds before accepting another input.
Because Kailh optical switches use light instead of metal, there is no vibration. Therefore, there is zero debounce delay. This allows for incredibly fast, instantaneous double-tapping, making them perfect for fast-paced games like Apex Legends. (If you play movement-heavy shooters, check out our guide to the Best Keyboards for Apex Legends).
2. Incredible Durability and Dust Resistance
Traditional mechanical switches are usually rated for 50 million keystrokes before the metal leaves begin to oxidize or bend. Because Kailh optical switches have no internal metal contacts to wear down, they are rated for over 100 million keystrokes.
Furthermore, many of Kailh’s optical offerings utilize their famous “Box” design. These switches feature a square wall around the stem, providing a dustproof housing that prevents debris and liquids from entering the switch mechanism.
3. Versatility and Hot-Swappability
Because the actual optical sensor (the light beam) is mounted directly to the circuit board, the switch itself is just a plastic housing with a spring. This means almost all optical keyboards are hot-swappable.
Kailh offers optical switches in linear, tactile, and clicky variations, with actuation forces ranging from a feather-light 35g to a heavy 80g. You can easily pull out a Kailh Optical Red and replace it with a Kailh Optical Blue without ever touching a soldering iron.
The Drawbacks of Optical Switches
While Kailh optical switches offer a number of benefits, they also have some potential drawbacks to consider.
1. The Compatibility Problem
The single biggest drawback of Kailh optical switches is cross-compatibility. You cannot put an optical switch into a standard mechanical keyboard.
If you have a keyboard designed for standard 3-pin or 5-pin mechanical switches, it does not have the infrared lasers on the circuit board required to read an optical switch. Furthermore, you cannot mix optical brands. A Kailh optical switch will not work in a Razer optical keyboard, and vice versa. If you buy a keyboard with Kailh optical sockets, you can only ever use Kailh optical replacement switches.
2. The Cost
Because they are a newer technology requiring specialized circuit boards, optical switches tend to be more expensive than traditional mechanical switches. This can be a barrier for some users who are looking to upgrade their keyboard on a strict budget.
(If you want to stick to traditional, highly compatible switches, read our guide to the 5 Best Linear Switches for Gaming).
