The File Extensions Database

.JAR File Extension

  • Developer by: Oracle
  • Category: Executable Files
  • Format: Zip

What is an .JAR file?

.JAR is Java Archive File

A JAR file is a Java archive (JAR) file used by the Java Runtime Environment (JRE), a framework used for executing Java programs. JAR files may serve as program libraries or as standalone programs that run if the JRE is installed on the computer or mobile device.

JAR files can contain .CLASS files, application resources, and an optional manifest file (META-INF/MANIFEST.MF). They are compressed using .ZIP compression and may optionally be digitally signed using the jarsigner tool included with the Java SDK. JAR files may be created with the jar tool, and they can be accessed using Java's java.util.jar API.

JAR files are used for some mobile games supported by Java-enabled mobile devices. They are also used by Mozilla Firefox, Thunderbird, SeaMonkey, and Sunbird to store themes and add-ons.

NOTE: The Java Runtime Environment is also referred to as the Java Virtual Machine (JVM). Sun Microsystems, the original developers of the JRE/JVM, were acquired by Oracle.

Programs that open Java Archive File
File Viewer Plus
Oracle Java Runtime Environment
Corel WinZip 23
WinRAR 5
Corel WinZip Mac 6.5
Oracle Java Runtime Environment
Oracle Java Runtime Environment
File Viewer for Android

How to solve problems with JAR files

  • Associate the JAR file extension with the correct application. On :
    Windows: Right click on any JAR file and then click "Open with" > "Choose another app". Now select another program and check the box "Always use this app to open *.JAR files". Mac: Right click (or Ctrl-click) the JAR file, then click "Open with" > "Other...". Then choose another program and check the "Always Open With" box. Linux: Right click on the file, and select "Open with" and choose another program. iPhone: Tap the file. If you do not see an app to open the file, then tap Share "Share" and choose an app. Alternatively, save the file. Then open the Files app Files app. There long-press on the file, then release your finger. You will see a black menu bar. Then tap "Share" and select an app. Android: Tap the Settings icon on your smartphone, then tap on the Apps section. There tap the Options icon in the top right-hand corner of the screen to change the default apps.
  • Update your software that should actually open .JAR is Java Archive File. Because only the current version supports the latest JAR file format. Search, therefore, e.g. on the Oracle manufacturer website after an available .JAR is Java Archive File update.
  • To make sure that your JAR file is not corrupted or virus-infected, get the file again and scan it with antivirus software.