Devices and methods are disclosed which relate to improving the efficiency of text input by generating a dynamic virtual keyboard. Certain examples display a soft keyboard on a touchscreen of a text-entry device. The touchscreen works with the soft keyboard as a form of text input. Keyboard logic on the text-entry device is programmed to change the footprint of each key within the soft keyboard based on the prior entry. The keyboard logic assigns a prediction value to each key based on a statistical probability that the key will be entered next. The touchscreen displays a dynamic virtual keyboard based on these prediction values. Enhancements include resizing keys and their respective footprints relative to their prediction value. Other examples exploit the possible character sequences and their probabilities in a language and restructuring the keyboard to make text input more efficient. The devices and methods use modeling techniques to dynamically generate the size of the characters on the keyboard.