An onscreen keyboard displays a virtual keyboard on the screen for users to enter input. It can be operated with the help of any pointing device such as a mouse, pen, joystick, etc. The keyboard is often resizable and customizable, allowing the typing mode, font, etc., to be changed as needed. In certain onscreen keyboards, especially those from Windows 7 and later versions, they are equipped with a predictive text engine, which helps in predicting the words the users may type.

There are several ways an onscreen keyboard can come in handy. It is useful, for example, for physically challenged users who have difficulty using a physical keyboard. It can also be used as an alternative or a temporary keyboard in case the physical keyboard becomes defective. Using an onscreen keyboard also prevents keystrokes from being captured by certain spyware programs such as keyloggers.

However, as typing on an onscreen keyboard is slower and more difficult than on a physical keyboard, most onscreen keyboards feature predictive text input.