Options.txt

options.txt is the file that stores all the options changeable in the in-game options menu and various other information the game needs to store after quitting. It is found in the .minecraft folder and can be edited with any basic text editor to change your options. Most settings can be changed in-game, but a few can only be changed by editing this file.

Options
Each line represents a single option or piece of data, with the option followed by a colon followed by the value of that option.

A list of all available key/button numbers is available at key codes.