Java JAR file format

A Java Archive — a ZIP bundling compiled .class files and a manifest.

MIME type: application/java-archive
Extensions: .jar
Category: Archives & compression

Magic-number signature

0x00000000

504B0304

PK··

'PK' — it is a ZIP

Inside the ZIP: 'META-INF/MANIFEST.MF' plus one or more '.class' entries.

About the Java JAR format

A JAR packages Java classes and resources into one distributable ZIP, optionally executable via its manifest's main class. It is recognized by a 'META-INF/MANIFEST.MF' entry alongside '.class' files.

Related formats

ZIP
Android APK
Java class file

Have a file that might be Java JAR? Identify it with the File Type Identifier — it reads the magic number locally, nothing is uploaded. Or browse all formats.