Keyboard Event Tester

What Is a Keyboard Event Tester?

A keyboard event tester lets you inspect the properties of any key press event directly in your browser. When you press a key, JavaScript fires a KeyboardEvent containing detailed information such as the key name, physical key code, numeric key code, and active modifier keys. This tool captures that event and displays every property in a readable format, making it ideal for developers who need to quickly look up key codes or debug keyboard shortcuts.

event.key vs event.code

event.key returns the logical key value - the character or action the key represents (e.g., "A" when Shift is held, "a" otherwise, or "Enter" for the Enter key). It is locale- and layout-aware.

event.code returns the physical key identifier based on the key position on a standard keyboard, regardless of layout or modifier state (e.g., "KeyA","ArrowLeft","Numpad0"). Use event.code when you care about the physical location (e.g., game controls), and event.key when you care about the character (e.g., text shortcuts).

Why Are keyCode and which Deprecated?

event.keyCode and event.which are legacy numeric properties that were not standardized across browsers and had inconsistent behavior for non-alphanumeric keys. The modernevent.key andevent.code properties were introduced as part of the UI Events specification to replace them. Both are still widely supported, but you should avoid using them in new code since they may eventually be removed from browsers.

Understanding event.location

The event.location property distinguishes between multiple physical instances of the same logical key. Location 0 is the standard position, 1 means the left side of the keyboard (e.g., Left Shift), 2 means the right side (e.g., Right Alt), and 3 means the numpad. This is useful when you need to differentiate between, for example, the left and right Control keys.

Common Use Cases for Key Code Lookup

• Building custom keyboard shortcuts in web applications
• Implementing game controls with arrow keys or WASD
• Debugging unexpected behavior of hotkeys in third-party libraries
• Testing accessibility of keyboard navigation
• Learning which key codes correspond to special or function keys
• Verifying modifier key combinations like Ctrl+Shift+Z