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Keyboard Latency Test

Tap any key and every press is timed from the moment your computer received it, through the browser, to the next frame on screen. You see the part of the input lag your computer adds — and an honest map of the parts a browser cannot see.

Updated · 3 sources

Click the box, then tap any key about 40 times at a relaxed pace. Every press is timed from the moment your computer received it to the moment the browser handled it and drew the next frame.

1 · Tap a key inside the box

—ms to screen (last press)

Click here, then tap Space or any letter.

Input delay
—
Key to frame
—
Worst 5%
—
Screen
measuring…
Presses
0
Press length
—

Where the delay comes from

  1. KeyboardScan, debounce and USB polling — not visible to a browser
  2. Computer → pagemeasured here
  3. Page → next framemeasured here
  4. DisplayScan-out and pixel response — needs a camera

Short answer

A website can only time what happens after the key press reaches your computer: the input delay and the wait for the next frame. On a healthy computer the input delay is a few milliseconds. The frame wait depends on refresh rate — a frame every 16.7 ms at 60 Hz, 6.9 ms at 144 Hz. The keyboard’s own delay needs hardware to measure.

How to use it

  1. Click the box. Presses are only measured while the box is active.
  2. Tap about 40 times. A relaxed, steady pace. Held keys and auto-repeat are ignored.
  3. Read the median. Input delay is how long the press waited before the page could handle it; key to frame adds the wait for the screen to draw.
  4. Check the worst 5%. Occasional long delays are what you feel as stutter. If they are high, something on the computer is busy.

What this keyboard latency test measures

Like any keyboard delay test that runs in a browser, it cannot see inside the keyboard — so it tells you which part it measured.

Total keyboard lag — from your finger to a change on screen — has four parts. This test measures the two in the middle precisely and is honest about the other two:

Stage What happens Measured here?
Keyboard Scanning the switches, debounce, waiting for the USB poll No — needs hardware
Computer → page The operating system and browser deliver the press Yes — input delay
Page → next frame Waiting for the browser to draw the next frame Yes
Display Scan-out and pixel response No — needs a camera

Input delay is the time between the browser receiving the key event and the page’s code running. On a healthy computer it is a few milliseconds at most. When the browser or computer is busy, presses queue up and this number grows — that is input lag your computer is adding.

Key to frame adds the wait until the browser draws the result. Most of that is set by your screen’s refresh rate. The pipeline below the stats splits the two parts apart.

Keyboard input lag test results explained

  • Low input delay, frame wait near one frame: the computer is not the problem. Remaining lag is in the keyboard or the display.
  • High input delay or a high worst 5%: something is keeping the browser busy. Close tabs and apps, plug in a laptop, and use a high-performance power mode, then run the input lag test again.
  • Worst 5% much higher than the median: occasional stalls — the stutter you feel more than the average.

How refresh rate changes the wait

Refresh rate Time per frame
60 Hz 16.7 ms
120 Hz 8.3 ms
144 Hz 6.9 ms
240 Hz 4.2 ms

The keyboard’s own delay

Reviewers measure a keyboard’s internal latency with a solenoid that presses the key and a device that records exactly when the computer receives it. A website cannot do that. You can check one part of it, though: a keyboard polling at 125 Hz can hold a press for up to 8 ms before reporting it, against 1 ms at 1000 Hz. Measure it with the Keyboard Polling Rate Test.

Keyboard response time test tips

Tap at a relaxed, steady pace — rhythm does not matter, but holding keys does: held keys and auto-repeat are ignored. Forty presses gives a stable median; more makes the worst 5% more reliable.

If something goes wrong

Input delay is high

Close other tabs and apps, plug in a laptop and use a high-performance power mode.

Key to frame is 10–17 ms

Normal for a 60 Hz screen, which draws a frame every 16.7 ms. A higher refresh rate shortens the wait for each frame.

FAQ

Can a website measure keyboard latency?

Only the part after the key press reaches your computer. The keyboard’s own delay — scanning the switches, debouncing and waiting for the USB poll — happens before that, and measuring it needs hardware such as the solenoid rigs reviewers use. This keyboard latency test measures the computer and browser side precisely and says so.

What is a good input lag?

On a healthy computer the input delay should be a few milliseconds at most, and the time to the next frame mostly depends on the refresh rate — under one frame on average.

Does a higher refresh rate reduce keyboard lag?

It reduces the wait for the next frame. At 60 Hz a frame comes every 16.7 ms; at 144 Hz every 6.9 ms; at 240 Hz every 4.2 ms.

Is a wireless keyboard slower?

It can be, but that delay happens before the press reaches the computer, so this test cannot show it. Compare polling instead with the Keyboard Polling Rate Test, using the USB receiver rather than Bluetooth.

Sources

Keyboard

Keyboard Polling Rate Test

Estimate your keyboard’s polling rate from how its key timings line up — 125 to 2000 Hz.

Keyboard

Keyboard Test

Press every key on a full keyboard picture — catches dead keys and double typing.

Keyboard

Keyboard Ghosting Test

Anti-ghosting and NKRO test: how many keys work at once, and which game combos get blocked.