How to test your keyboard
- Open the page on a computer with the keyboard you want to test.
- Press each key in turn and watch it light up on screen.
- Look for keys that stay unmarked, as they did not register.
- Press Reset to clear the marks and test again.
Finding dead or sticky keys
Work along each row from left to right, pressing every key once. A working key lights up while pressed and stays marked afterwards, and the counter shows how many keys you have tested. When you reach the end, any key still unmarked did not reach the browser. Try it a few more times, pressing firmly in the centre, before deciding it is dead.
For sticky keys, watch the on-screen key as you let go. If it stays lit after you have lifted your finger, the key is not springing back properly. The last key pressed and its code are shown too, which helps when a key types the wrong character.
When to use a keyboard tester
- Buying a second-hand laptop or keyboard on Facebook Marketplace or eBay, before you hand over the money
- Checking a new mechanical keyboard on arrival, while it is easy to return
- After a spill: once dried out, test every key, as damage often shows on a few keys only
- Tracking down a key that sometimes types twice or not at all
- Checking a UK keyboard really is UK layout, with the £ on Shift and 3 and the @ next to the semicolon
Keys that never light up
Some keys are handled by the keyboard or laptop itself and never reach the browser, so they cannot show up here even when they work. The Fn key is the usual one. Many media keys, brightness keys and special laptop keys are the same. Test them by checking whether they do their job, such as changing the volume.
Some key combinations are also caught by your operating system before the page sees them, such as the Windows key or Cmd and Tab. This tester works with a physical keyboard on a computer. The on-screen keyboard on a phone or tablet is a different thing and is not supported. If a key works here but not in one program, the problem is that program's settings, not the keyboard.
Questions people ask
Why does the Fn key not light up?
Fn is handled inside the keyboard and never sent to the browser. Check it works by using it with another key, such as a volume key.
Can I test my phone keyboard?
No. It is designed for physical keyboards on a computer, including keyboards plugged into a laptop.
Is the layout UK or US?
The on-screen layout is a UK keyboard, with the £ sign, a short left Shift and the larger Enter key.
How do I start again?
Press Reset to clear all the marked keys and the count.
What is the key code for?
It shows exactly which key the browser received, which helps when a key types the wrong character or two keys seem to be swapped.