Keyboard Latency Test

The Keyboard Latency Test is a free browser-based diagnostic tool that measures the input processing delay between your physical keypress and when the browser's JavaScript engine processes the event. This delay, measured in milliseconds, reveals how quickly your keyboard input travels through the entire chain — from the physical switch actuation, through the keyboard's microcontroller, over the USB or wireless connection, through the operating system's input stack, and finally into the browser's event loop.

When you press a key, the browser attaches a high-resolution timestamp to the KeyboardEvent object via the event.timeStamp property. Our tool immediately compares this timestamp against performance.now() — the browser's own high-resolution clock — when our JavaScript handler processes the event. The difference between these two values represents the event loop processing latency: the time the event spent waiting in the browser's internal queue before our code could react to it.

Understanding keyboard latency is critically important for competitive gamers. In fast-paced first-person shooters, real-time strategy games, and fighting games, every millisecond of input delay directly affects your reaction time and gameplay performance. A keyboard with 1ms of latency gives you a measurable advantage over one with 20ms of latency, especially when combined with a high-refresh-rate monitor and a low-latency mouse.

The tool displays four key metrics in real-time. Current Latency shows the delay measured on your most recent keypress. Average Latency provides a running mean across all your samples, which becomes more stable as you press more keys. Min Latency shows the absolute lowest delay your setup has achieved — this represents the best-case performance of your keyboard. Max Latency reveals the worst-case spike, which often indicates the browser was briefly busy with other tasks when your keypress arrived.

Several factors contribute to keyboard latency that are entirely outside your keyboard's control. Background browser processes, other open tabs consuming CPU resources, browser extensions intercepting keyboard events, operating system power management throttling USB polling, and even the specific USB port you are connected to can all influence the measured latency. For the most accurate reading, close unnecessary tabs and extensions before testing.

Wired keyboards consistently achieve lower latency than wireless alternatives. A direct USB connection eliminates the encoding, transmission, and decoding overhead of wireless protocols. Among wireless technologies, 2.4GHz proprietary dongles (like Logitech Lightspeed or Razer HyperSpeed) typically add only 1-2ms of overhead, while Bluetooth connections can add 10-30ms due to the protocol's higher-level abstraction and power-saving intervals.

To get the most reliable results, we recommend pressing a single key repeatedly at a moderate pace — roughly one press per second — for at least 30-50 samples. This gives the average time to stabilize and filters out anomalous spikes caused by temporary system activity. The event log at the bottom shows every individual measurement with color coding: green for excellent latency under 5ms, yellow for moderate latency between 5-15ms, and red for high latency above 15ms.

A latency rating badge automatically appears once you have enough samples, classifying your keyboard's performance as Excellent (under 2ms), Very Good (2-5ms), Good (5-10ms), Average (10-20ms), or High Latency (above 20ms). Keep in mind that these ratings reflect the browser-level processing delay, not the absolute end-to-end hardware latency, which requires specialized measurement equipment like an oscilloscope and a high-speed camera.

All measurements are performed entirely within your browser using the high-resolution Performance API. No keypress data, timestamps, or personal information is ever transmitted to any server. Your privacy is completely protected. For additional keyboard diagnostics, try our Keyboard Polling Rate test to measure your keyboard's USB report frequency, or our Keyboard Ghosting Test to check N-Key Rollover support.