Key Chatter Test
Find keys that register twice from a single press — time every keystroke and flag double-presses under 40 ms.
How to use this test
Click Start Chatter Test, then type a few normal sentences in the box and tap each suspect key slowly — about once per second. The test flags any second press of the same key that arrives within the selected threshold.
How the measurement works
The tool times every keydown event and compares it with the previous press of the same key. A second press inside the threshold (30, 40 or 50 ms) is logged as a double-press with its shortest gap. Held-key repeats are ignored, so a long press never counts as a fault.
How to interpret results
One or two suspect keys — usually the ones you use most — point to worn or dirty switches. Many keys at once points to something shared: firmware debounce, the connection, or software on the computer. Gaps under about 30 ms are almost never human.
Troubleshooting tips
If a key still doubles in a text editor but the test is clean, repeat the test on another computer, switch off Windows Filter Keys, blow compressed air around the switch, and test again after each fix.
Related tests
You can also browse every utility from the complete tool index.
Related guides
- How to Fix Keyboard Double Typing — A step-by-step fix for keyboards that type double letters: confirm the cause, clean the switch, correct the settings, and replace only when needed.
Common key chatter questions
How do I test my keyboard for double typing?
Open the Key Chatter Test, start listening, then type a few normal sentences and tap each suspect key slowly — about once per second. The test flags any second press of the same key that arrives within 40 ms and lists the suspect keys with their shortest gap.
Read full answer →How do I fix keyboard chatter on Windows 11?
First confirm it with a chatter test on two computers. Then clean around the switch with compressed air, check the repeat-delay setting in the Windows keyboard control panel, update or reinstall the keyboard driver, and on a hot-swappable board try a different switch before replacing the keyboard.
Read full answer →What causes keys to type twice?
Usually contact bounce: the switch contact bounces and the keyboard's debounce does not filter it, so one press registers twice. A repeat delay set too short in the operating system can look the same — the difference is that a short repeat delay only doubles when you linger on the key, while chatter doubles even on sharp single taps.
Read full answer →What is keyboard chatter?
Key chatter is when one physical keypress registers as two or more presses because the switch contact bounces and the keyboard's debounce does not filter it. It is most common on worn mechanical switches.
Read full answer →