Why this tool is useful
Use this tester to identify a key that does not register, repeats unexpectedly or reports a different physical code after changing a keyboard layout.
Browser & Privacy · runs locally
Keyboard Event Tester
Check which physical keyboard keys reach this browser, including key codes, repeats and release events, without recording typed text remotely.
Ready. Your working data stays in this browser.
How it works
After you start the test, a focused local panel listens for keydown and keyup events. It keeps only a bounded in-memory event summary and sends nothing over the network.
Practical example
Press and release the left Shift key, then press A. The result distinguishes ShiftLeft from KeyA and reports whether either key generated an automatic repeat.
Validation
The calculation is deterministic and explains validation errors instead of silently changing invalid input.
Privacy boundary
Input and output remain in this tab. Copy and download happen through browser APIs without a server upload.
Result passport
Every run reports its tool mode, timestamp and input/output size so transformed data can be audited.