offlinewebtools.com browser-local workbench

Keyboard Rollover Tester

Check how many keys your keyboard can register simultaneously and monitor live key states.

Shipped

Browser local

Press and hold any combination of keys. Release everything and press again to reset the current list.

Currently pressed

None

No key activity yet.

What this tool does

Keyboard Rollover Tester helps you check how many keys your keyboard can register simultaneously and monitor live key states.

What you get

Keyboard Rollover Tester produces a direct output in this page and keeps all processing on your device, with nothing uploaded to our servers.

If this tool misbehaves, share a quick summary so we can investigate. We include the tool URL automatically—no need to copy and paste.