Wired vs. wireless keyboards: Latency gap persists, but most users may not notice

Engadget reported that USB wired keyboards still exist even as Bluetooth is available on nearly every device. Wired keyboards are common, and some high-end models offer no wireless protocol at all. Performance-focused gaming keyboards are the least likely to have a wireless option, a fact that points to the main issue wired devices avoid: performance problems.

Bluetooth is known for latency. A Bluetooth speaker or pair of earbuds connected to a video may deliver audio out of sync, and the same delay applies to mouse clicks and keypresses. The delay can add a few extra milliseconds before input reaches a computer. In writing or editing spreadsheets, users will almost never notice it. In gaming, where reaction time is key, Bluetooth latency can quickly lead to a lost match or a character death. Musicians using keyboards with a digital audio workstation may also need lower latency for precise timing.

Not all wireless keyboards rely on Bluetooth. Many include a 2.4GHz connection, which usually requires plugging a small dongle into a USB port. Engadget reported that 2.4GHz is much faster than Bluetooth and often acceptable for gaming and other low-latency tasks.

For people who do not game, Engadget reported, the topic can be ignored, and they can use whichever keyboard connection type they prefer. For those who play games and want to optimize a setup, it is useful to compare the two most common wireless connection types on keyboards with a wired keyboard.

Keyboard performance involves more than connection type. Actuation speed measures how quickly a key activates when pressed. Debounce rate measures how the keyboard filters out accidental repeat presses and other chatter. Polling rate measures how often the keyboard reports back to the host device. All of these can affect overall latency. Engadget reported that midrange and pro-grade keyboards have addressed such issues, for example by using Hall effect switches for customizable actuation points and high polling rates to prevent bottlenecking. Bluetooth limitations remain, which is why many gaming keyboards do not offer Bluetooth and plenty of non-gaming mechanical keyboards also lack it.

Between a wired and Bluetooth connection, Engadget reported, the wired option will invariably be better for performance. The same applies to other Bluetooth uses. Listening to music through AirPods will never sound as good as plugging in a pair of wired headphones, and gaming mice and headsets face the same latency concerns as keyboards. A Bluetooth connection may introduce as little as 8 milliseconds of latency, practically nothing compared with human reaction speed of 150 to 250 milliseconds, but it can easily top 200 milliseconds, enough to make many games unplayable.

Bluetooth remains because most people are willing to trade performance for convenience, Engadget reported. The article's author listens to music with wireless earbuds to avoid wires while walking to the train and types articles on a Bluetooth keyboard because noticing the performance drop would require typing faster than is humanly possible. Gaming is a specialized case in which convenience becomes a burden. A missed headshot in a competitive shooter because of added latency can lead to death when the opponent shoots back, followed by a drop in seasonal rankings. Bluetooth can be adequate for turn-based games, RPGs and other titles where lightning-fast reactions matter less.

2.4GHz connections are fast, but they are not a fix-all solution. Engadget described 2.4GHz as the Goldilocks of keyboard and mouse connections. A keyboard with a small USB dongle that plugs into a computer to create a wireless connection is an example. Unlike Bluetooth, there is no single, unified standard for 2.4GHz. It refers to the portion of the radio spectrum these devices occupy, and each manufacturer implements its own 2.4GHz connection. A Logitech keyboard cannot be mixed with a Keychron 2.4GHz dongle.

Bluetooth itself technically relies on the 2.4GHz radio band but is a proprietary technology licensed to device manufacturers. Engadget reported that Bluetooth is focused on maintaining a robust connection with compressed data at the cost of performance.