Keyboard Ghosting Demonstration

Using This Demonstration
Click on the keyboard shown above. It will then show what keys are being pressed on your keyboard (or to be more specific, the ones that are being passed to your web browser). You can use this to see if there are certain key combinations that fail to work correctly.
How To Hunt For Ghosts
Ghosts can be somewhat elusive. Just because you find some combination of 6 keys that reports correctly does not necessarily mean that every combination of 6 works. In fact, the most straightforward keyboard design has thousands of 3-key combinations that do not work! That is a lot, but it is still less than 5% of the total number of 3-key combinations.
A quick way to find problematic combinations is to press and hold ASDW (the most popular keys for moving around in games), and then while holding those down, press every other key in turn. If you find a key that does not work, try releasing some of the ASDW keys. Odds are high that you will find a 3-key combination that fails.
If you have an application that uses other combinations of keys, be sure to try those too!
What Causes Ghosting?
For more information on what causes ghosting and strategies that keyboard designers use to reduce the problem, see Keyboard Ghosting Explained.
Link To This Demo
To paste the link in email or IM:
To embed the link in a web page:
Caveats
Limitations of this demonstration:
1. Some keys are not available to web pages. For example, the demo will usually not be able to see when the print screen key is pressed.
2. Some keys will remove focus from the web page. For example, pressing the windows key will usually display and give focus to the windows start menu. To continue using the demo, move focus back to the web page by clicking on the demo.
3. Some keys are ambiguous to the web page. For example, web pages usually can’t tell the difference between the left and the right shift keys; they only know that one of the shift keys was pressed. For these kinds of keys, the demo will display both members of the ambiguous set. For the example of the shift keys, the demo will highlight both the left and right shift keys as being pressed regardless of which shift key was actually pressed.