.JSON File Extension

Data interchange format used for representing simple data structures and objects; saved in a lightweight, text-based, human-readable format; originally based on a subset of JavaScript, but is considered a language-independent format.

JSON files are often used in Ajax Web application programming. They may also be used by other applications as an alternative to .XML files.

NOTE: Mozilla Firefox saves bookmark backups using JSON files. The files are saved to the Firefox user profile directory within a folder called bookmarkbackups. You can also make manual backups of Firefox bookmarks and import them into a different copy of Firefox. To import, open the bookmark Library, click the import/export button in the top bar, choose Restore → Choose File..., and then select your JSON backup file.