How to Test Every Key on Your Keyboard

Start with a complete key check

Open the keyboard diagnostic and press keys one at a time. A key should enter the Pressed Now state while held and remain marked Tested / Released after keyup. Work through the main letter block, number row, modifiers, navigation keys, arrows, function row, and numpad instead of testing only the key you suspect.

The visual layout uses event.code, which identifies a physical key position. The Latest Key Event panel also shows event.key, the interpreted value. That distinction matters when a keyboard layout maps the same physical position to a different character.

• Test left and right Shift, Control, Alt, and Meta separately.
• Check Digit keys separately from Numpad keys.
• Release each key and confirm it leaves Currently Pressed.
• Use Reset Test before repeating a controlled pass.

Understand browser limitations

A webpage can record only events the browser and operating system deliver to it. Some function keys and shortcuts may be intercepted for browser navigation, developer tools, window management, media control, or operating-system features. ReflexMint prevents default function-key actions when the browser permits it, but it cannot override shortcuts that never reach the page.

An untested key is therefore not proof of failed hardware. Retest it in another browser, a simple text editor, or the operating system's keyboard settings before drawing a conclusion.

• Ctrl+L, Ctrl+T, Ctrl+W, Alt+F4, and system-key combinations may remain reserved.
• Laptop Fn layers can change what a function-row key sends.
• International layouts may produce codes or key values that differ from the printed legend.

Check the connection and setup

For an external keyboard, reconnect the cable or receiver, try another USB port, and check battery level for wireless models. Bluetooth power saving and weak connections can make intermittent behavior look like a defective switch. If possible, compare the same keyboard on another device and a known-good keyboard on the original device.

For laptop keyboards, remember that function lock, accessibility settings, remapping software, and manufacturer utilities can alter key behavior without a physical fault.

What the result can tell you

Consistent detection across repeated presses indicates that the browser is receiving the expected events. A key that never appears across multiple applications and devices deserves closer hardware investigation. A key that appears twice, remains logically pressed, or disappears only in combinations may instead suggest chatter, a missed keyup event, shortcut interception, or rollover limits.

A browser test is a useful observation tool, not a hardware certification. Record the exact key, combination, device, connection, and application where the issue occurs; that evidence is more useful than a single pass/fail label.