Keyboard Latency Tester

True input latency, the time between your finger physically pressing a switch and the signal reaching your operating system, technically requires specialized hardware to measure with full precision. What a browser-based tool like this one can measure honestly is the interval between consecutive keydown events as your operating system reports them, which is still genuinely useful: it reflects your keyboard's polling rate, its connection type, and how consistently it registers repeated presses.

A wired keyboard with a high polling rate typically reports very short, consistent intervals when you tap a key at a steady rhythm. A wireless keyboard, especially one connected over Bluetooth rather than a dedicated USB receiver, often shows longer and less consistent intervals because of the extra step of wireless communication. Gamers care about this because lower, more consistent latency means faster reaction times translate more reliably into in-game actions. Competitive typists care because a keyboard with inconsistent response times can quietly cap how fast you're able to type, no matter how good your technique is.

To run the test, click Start, then press the same key repeatedly at a steady, comfortable pace for several seconds. The spacebar or any letter key works well. KeysInFlow records the time between each keypress, averages your recent readings, and color-codes the result so you can see at a glance whether your keyboard is performing well.