Keyboard Check Lab

Browser-observed input timing

Keyboard latency & repeat rate test.

Measure repeat delay, event spacing, timing consistency, and tap intervals without installing software or sending keystrokes anywhere.

Ready to measure
  1. 1Start
  2. 2Hold one key
  3. 3Tap 8 times
  4. 4See conclusion

Keyboard latency and repeat rate tester

Start, then hold one letter key for three seconds. Release it and tap the same key 8–10 times.

Test key—0 events observed

This measures browser-observed event timing. It cannot measure physical switch latency, USB polling rate, or end-to-end input lag.

Read the result correctly

Useful for comparisons—not a hardware latency verdict.

The page measures timestamps assigned after keyboard events reach your browser. Use it to compare repeat behavior under the same conditions, not to claim an absolute end-to-end latency number.

REPEAT RATE

Events per second

Estimated from the median gap between browser-generated repeat events while one key is held.

INITIAL DELAY

Time before repeat

The observed time from the first keydown event to the first autorepeat event. Operating-system settings strongly affect it.

VARIATION

Timing consistency

Standard deviation of repeat intervals. Background work, power saving, and browser scheduling can all add variation.

Method

Compare like with like.

  1. Close games or demanding applications that could interrupt browser scheduling.
  2. Select Start test, then hold one letter key for about three seconds.
  3. Release the key and tap the same key naturally 8–10 times.
  4. Reset and repeat the test at least three times in the same browser.
  5. When comparing keyboards, keep the computer, browser, port, and operating-system repeat settings unchanged.
Not measured: switch actuation latency, scan rate, USB polling frequency, display latency, and the delay between physical movement and the first browser event.

For repeated letters or suspicious double inputs, use the keyboard chatter test. For missing combinations, read the rollover and ghosting guide.

FAQ

Timing-test limitations.

Can a browser measure true keyboard latency?

No. The event has already passed through keyboard hardware, firmware, USB, the operating system, and browser processing before this page receives it.

Does the repeat rate equal USB polling rate?

No. Key repeat is created by the operating system and delivered through the browser. A 20 Hz repeat result does not mean the keyboard uses a 20 Hz USB polling rate.

Why do results change between runs?

Browser scheduling, background applications, CPU power states, wireless conditions, and operating-system settings can all change observed event timing. Compare several runs rather than one number.

Are my keystrokes uploaded?

No. Timing samples remain in memory inside this tab and are cleared when you reset or leave the page.