A key seems to miss a press, or a mouse button behaves differently than you expect. Before changing settings, make a simple observation: does the input reach the window you are using?
Input Lab shows keyboard presses, held keys, mouse buttons and scroll events in one place. It helps you inspect what the application receives, rather than guessing from an unresponsive action in another program.
This walkthrough covers Input Lab 1.0.0. It is an input check, not a measurement of hardware latency or a certification that a device is fault-free.
Start with a short keyboard check
Install Aelrox, find Input Lab, and open it on your desktop. Select Start keyboard test and keep its window focused.
Press A, S and D separately, releasing each before the next. Watch the keyboard matrix and the recent-event display. A tested key receives a green marker; its small number counts presses excluding repeats. Held now describes keys that remain down, while Unique keys counts distinct keys observed during the session.
Next, hold Shift and press A. Look for both physical positions in the matrix and review the event monitor. The matrix uses a US-style physical layout; labels printed on another keyboard layout may differ. Use the reported key codes when the diagram does not match your keycaps.
Distinguish holding a key from pressing it repeatedly
Hold A briefly, then release it. The operating system may send repeat events while the key stays down. Show key repeats in log makes those events visible in the event monitor.
Repeated events during a deliberate hold are not proof of switch chatter. To investigate a suspected duplicate press, release the key fully between attempts and review what was observed. This tool alone cannot determine whether an unexpected event came from the switch, a driver or software settings.
Check mouse buttons and scrolling
Use the dedicated Mouse test area. Click left and right once, try the middle button, then scroll up and down. Review the button counts and Wheel X/Y values. Move the pointer inside the area to see its trail.
| Display | Useful interpretation |
|---|---|
| Left, Middle, Right | Pointer presses observed inside the test area |
| Back, Forward | Side-button events, if delivered by the system |
| Wheel X/Y | Reported scrolling values, not physical wheel distance |
| Double-clicks and press interval | Observed timing, not a hardware fault diagnosis |
Keep the pointer inside the test area when comparing attempts. System or browser actions may reserve side buttons, so an absent event is a reason to investigate, not proof that the button is broken.
End the test and interpret missing keys
Press Esc to end keyboard testing. Switching to another window also ends capture and releases the held-key display. Use Reset session before starting a fresh check.
Fn, some media keys and operating-system shortcuts may never reach the app. Input Lab observes the focused window; it does not claim to capture every system-wide key or measure polling rate. Avoid entering passwords or private text into any test session.
Open Input Lab when you want a clear record of what a press or scroll does in this window, then compare that observation with the behavior in the program where you noticed the problem.