PHAR file contains PHP files archived (zip or rar archive) compressed using either bzip or gzip2 compression algorithm. This type of file supports checksums. PHAR archives can store images, stylesheet files or other files required for PHP application to run properly. Archive must contain a PHP file stub describing application loading process, a manifest file describing contents of the archive and archived files. Such archive files are created and opened with PHP tool called PHAR, available in PHP 5.3. PHAR archives are similar to Java JAR archives and can be run with PHP.

PHAR files are used for distributing PHP applications as a single file. PEAR (PHP Extension and Application Repository) is a popular tool for managing PHP extensions that uses PHAR file format. APC tools can be used to optimize executable PHP code to further enhance application’s performance by up to six times. Some well-known applications, such as PhpMyAdmin, Composer or PHPUnit are disributed using PHAR archives.