Files with the .TXT extension contain pure, unformatted text. This is the most basic format for saving text. It can be viewed and created by most text editing software, and, if using the default fonts, displayed even by web browsers and lots of other software and devices. Many other types of files are saved using the TXT format.

TXT files are usually used for saving simple text that does not require special formatting, such as notes or README.txt files, often attached during distribution of various applications for the purposes of providing important information. The standard applications for creating TXT files built into the operating system are the Notepad and Wordpad in Windows and TextEdit in MacOS X.