The term key rollover refers to the number of keys that can be simultaneously registered by a keyboard. For example, 6-key rollover means that you can press any six keys at once, and all will be registered correctly. Note that it is not necessarily an upper limit – there is a chance that some combinations consisting of more than six keys also work, but there is no guarantee. A more detailed explanation, common rollover types and recommendations for your next keyboard purchase can be found in the article key rollover explained.
While most manufacturers adhere to the given definition of key rollover, some have used rather unconventional counting to achieve a higher key rollover value. One such alternative counting method includes for example the combination possibilities of the modifier keys (Ctrl, Alt, Shift, etc.) and adds them to the common key rollover count. Obviously, this doesn’t fit the definition.
Online Key Rollover Test with Visual Keyboard
The following online key rollover test makes it easy for you to verify specifications from manufacturers. To begin with the test, click on the start button. Then start typing. The tool captures all your inputs and shows recognized keys and the overall amount of simultaneously pressed keys. You can easily try out various key combinations and test how many keys your keyboard can handle at once.
Usage of the Key Rollover Test
- JavaScript is required for execution.
- This page was tested with most common, modern browsers. We recommend to use Google Chrome or Mozilla Firefox.
- In general, browsers can not detect, whether the print screen key is pressed or not. Therefore, the same goes for the online key rollover test.
- No localization is performed – the keyboard for visualization uses an English (US) layout and the names of captured keys depend on your browser’s settings.
- Due to technical limitations of a web browser, not all keys can be captured. Therefore, some keys on your keyboard might not be recognized or could end up with an incorrect label. Note that keyboard software, operation system and browser affect the sent signals.