Keyboard Chatter Test
A keyboard double typing test. Chatter is one press that registers as two, usually from a worn or dirty switch. Pick a key and press it 30 times at a normal pace; the page flags any second press that arrived too soon and shows how long each press and gap lasted, so you can tell a switch fault from a fast finger. Every other key is watched the whole time too.
1. Test
Press each key once. Green means your browser received it. Striped keys (like Fn) never reach a browser, so they are not counted. When you are done, press I've pressed every key so anything missing is reported.
While the test runs, keys do nothing else on this page. Stop with the button, or hold Escape for two seconds.
Advanced
Last events, as your browser delivered them (shown live, never saved):
| type | key | code | location | repeat | modifiers | time (ms) |
|---|
2. Result
Is it the keyboard or the computer?
Save the JSON here, run the test again with the keyboard on another computer or USB port, then load the first file. If the same problem shows up on both, it follows the keyboard.
In this browser
About the Keyboard Chatter Test
How to use it
- Press Start test. The Chatter check tab is already open.
- Press the key you suspect once to choose it, then keep pressing it at a normal pace until the counter reaches 30.
- Read the verdict for that key, then press Check another key to test the next one.
- Leave the test running while you type normally for a while: chatter on any key is still caught.
What this page focuses on
- Guided check: press one key 30 times and get a verdict for that key with the evidence (time between presses, how long the key was released).
- Uses press length and release gap, not only time between presses, so a very short bounce is told apart from a quick double tap.
- Watches every key in the background while the test runs, because chatter often comes and goes.
- Adjustable threshold (default 45 ms) and an export you can send to a seller or manufacturer with a warranty claim.
Reading your result
- No chatter: None of the presses arrived within the threshold of the one before. The key is fine at this threshold.
- Possible chatter: At least one press followed the previous one too quickly. The evidence shows the gap and how long the key was released; releases of a few milliseconds are switch bounce, not your finger.
- Chatter that comes and goes: A key can pass the 30-press check and still chatter later. Watching it during normal typing, or repeating the check another day, catches it.
What causes keyboard chatter?
Worn or dirty switch contacts that bounce when pressed or released. Compressed air or switch cleaning sometimes fixes it; hot-swap keyboards can replace the switch.
Could it be software instead?
Rarely. To check, save the result here, test the keyboard on another computer or USB port, and load the first result: if the same key chatters on both, it follows the keyboard.
What threshold should I use?
The default 45 ms catches most chatter without flagging deliberate fast taps. Raise it if a key only double types sometimes; lower it if you type very fast and see false alarms.
What a browser cannot test
Fn is handled inside the keyboard and never reaches any web page. Brightness, volume and media keys are often taken by your system first. Browser and system shortcuts (Ctrl+W, Alt+Tab, the Windows key) are kept by the browser or system, except in Full keyboard mode in Chrome and Edge. Ctrl+Alt+Delete cannot be tested anywhere. No web page can measure keyboard latency, scan rate or polling rate, or certify a rollover (NKRO) rating, and this one never claims to.
Privacy
The test runs entirely in your browser. Nothing you press is uploaded, and nothing is saved after you close or refresh the page. Saved files are created on your device and only go where you send them.