AI-rewritten: This is a summary of an article from Ars Technica, rewritten by AI (Qwen, running locally) to make it easier to read. The facts come from the original article – read it for the full story.

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Over the past six years, keyboards featuring optical, Hall-effect, and other "contactless" switches have become common, often costing more than traditional mechanical boards. While manufacturers promise theoretical advantages for gamers, daily differences can be subtle. Traditional mechanical switches use two metal leaves that touch to close a circuit when pressed. This physical contact can degrade over time due to oxidation or corrosion, though newer standard mechanical switches rated for 100 million keystrokes may last as long as contactless options.

Contactless switches avoid metal-on-metal contact by using light beams or magnets instead. They require specific PCBs that are less common than those for standard switches, and hot-swappable versions are harder to find. While some users claim these switches feel smoother because no leaves touch, friction from springs and stems can also create resistance. Factors like force curves and materials often impact the feel more than the switch type itself.

Many contactless switches offer customizable actuation points, allowing users to set keys to trigger at different distances. However, software settings may not always match the actual physical distance; testing showed differences of fractions of a millimeter between app settings and real-world performance. Some models also support analog input, detecting how far a key is pressed rather than just whether it was hit, similar to a joystick feature unavailable on traditional keyboards.

Contactless switches are popular among gamers because they often eliminate debounce delay. Debounce delay is the time needed for a mechanical keyboard to stop interpreting rapid metal leaf bounces as multiple inputs. While standard switches may have delays of 5 ms to 20 ms, some claim less than 1 ms. However, overall latency depends on travel time, polling rates, and other hardware factors, which matter most for professional gamers who have already optimized their GPU, CPU, and monitor.