THE PRACTICAL GUIDE · NORMANDIN SYSTEMS
Get more from Keycode info
Keycode info: Find the javascript keycode, code, location and modifiers of any pressed key. Keyboard events expose both interpreted characters and physical-key identifiers, which helps debug shortcut handling across layouts. Hardware diagnostics are easier to interpret when the environment is controlled. Browser permissions, operating-system shortcuts, device settings, and physical connections can affect what a web tool observes. Begin with a known working setup or a repeatable test pattern, then change one condition at a time. Record the device model and the symptoms you see rather than treating a single result as a complete diagnosis. If the test suggests a problem, repeat it with another application, connection, or device where practical to distinguish hardware behavior from software limitations.
Guide updated October 13, 2026
How to use this tool
- Begin with a representative input. For a practical test, use: Press the A key with and without Shift. Replace demonstration values only after you understand the output.
- Prepare the device and select the relevant test mode or input values, checking any browser permission prompt before proceeding.
- Run a small repeatable test and observe the displayed feedback while changing only one variable at a time.
- Repeat an unexpected result in another suitable application or with a known working device before drawing a hardware conclusion.
SEE IT IN PRACTICE
A worked example
Press the A key with and without Shift
JavaScript keyboard-event information such as key and code
Compare event.key and event.code deliberately: one reflects interpreted meaning while the other identifies the physical key position.
Control the observation conditions
Use one device and one clear test condition at a time. For displays, vary solid colors and account for dust or reflections. For keyboards, confirm page focus and compare individual keys before combinations. For serial devices, match connection parameters and use a known protocol message. For resistor markings, confirm band count and orientation rather than guessing from a single color.
Turn an observation into a reproducible report
Record the device, connection, settings, and exact steps. Note whether the result persists in another appropriate application or with a known working comparison device. A missed key event does not automatically mean a broken switch, and a raw serial stream does not explain its protocol by itself. Use the tool to narrow the question, then apply a suitable independent check where the result matters.
When this tool is useful
- Debug a shortcut handler
- Compare key and code values
- Inspect modifier state
Tips for a better result
- Deprecated keyCode values should not be treated as the sole basis for modern keyboard handling.
- Browser support and operating-system interception can limit what a web-based hardware test can observe.
- Write down the connection, device settings, and repeatable symptoms so troubleshooting does not depend on memory alone.
Frequently asked questions
What is the difference between event.key and event.code?
event.key describes the interpreted key value, while event.code identifies the physical key position. Layout and modifiers can therefore change key without changing code.
Why does behavior differ between browsers?
Browsers expose different device APIs and may apply different permission or security restrictions. Operating systems can also reserve certain inputs, so the page may not receive every event or device capability.
What makes a useful troubleshooting record?
Note the device model, connection type, operating system, browser, settings, and exact steps that reproduce the issue. Include whether the same behavior occurs with a different cable, port, or application.
What happens to the information I enter?
The utility processes your input in this browser. Some tools retain field values in browser storage or the URL; avoid entering secrets in shareable fields. Page and asset requests still go to the hosting provider. Read the privacy and offline-use notes for details.