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How to Extract JAR Files on Android

Save selected classes, manifests and resources—or unpack the complete archive—without modifying the original JAR.

Quick answer

Open the JAR, choose what you need, then extract

A JAR is a ZIP-based archive, so its files can be unpacked into normal folders. In Jar File Opener, select a JAR from Android storage, browse its directory tree, choose individual entries or the complete archive, and save them to a separate destination folder. Keep the original JAR until you confirm that the extracted files are complete.

Extract a JAR file on Android

  1. Install and open Jar File Opener on your Android phone or tablet.
  2. Choose Open JAR File, then locate the archive with Android's system file picker.
  3. Browse the archive before extracting. Check META-INF, package folders and resource directories to confirm that you selected the correct file.
  4. Select the entries you need, or choose the option to extract the complete archive when you need every folder and file.
  5. Pick a new destination folder with enough free space. Avoid a folder that already contains files with matching names.
  6. Wait for extraction to finish, then open the destination folder and verify a few expected entries.

Extract selected files or the complete archive?

Selected entries

Best for quick inspection

Extract only a manifest, image, configuration file or class you need. This uses less storage and makes the result easier to review.

Extract all

Best for a complete copy

Recreates the archive's stored directory tree. Use this for a full audit, resource inventory or offline examination.

META-INF/

Package metadata

Contains the manifest and may contain signing or service-provider information. Reading these files does not execute Java code.

Package folders

Classes and resources

Paths such as com/example/ commonly contain CLASS files alongside images, templates and configuration data.

What the extracted folder should look like

Extraction normally preserves the entry paths stored in the archive. For example, extracting sample.jar may create this directory tree:

sample-extracted/ META-INF/ MANIFEST.MF com/ example/ Main.class App.class config/ application.properties images/ icon.png

The extracted directory is not a new JAR. It is a normal collection of folders and files. Editing the extracted copy does not automatically update the original archive.

Extract a JAR on Windows, macOS or Linux

When a JDK is installed, Oracle's jar tool can list the contents, extract everything, extract one entry or choose a destination directory. Use --keep-old-files when you do not want existing destination files replaced.

jar --list --file app.jar
jar --extract --file app.jar --dir app-extracted
jar --extract --file app.jar META-INF/MANIFEST.MF
jar --extract --keep-old-files --file app.jar --dir app-extracted

Why JAR extraction may fail

  • Incomplete or damaged archive: the JAR may have been interrupted during download or may contain invalid directory metadata. Download it again from the original source.
  • Not enough free space: compressed archives can expand to a much larger size. Choose a destination with room for the uncompressed contents.
  • Storage permission denied: select a destination Android allows the app to write through the system file picker.
  • Existing files: an entry may have the same path as a file already in the destination. Extract into a new empty directory when the desired overwrite behavior is uncertain.
  • Duplicate entry names: a malformed or unusual JAR may contain the same path more than once. Some extraction tools keep only the later copy.
  • Unexpected empty folders: some ZIP-based archives do not store folder records separately; folders may appear only when a contained file is extracted.
  • Wrong file type: renaming an unrelated file to .jar does not turn it into a valid archive. Check its signature with the File Inspector.

Extract unknown JAR files cautiously

Static extraction does not itself run the contained bytecode, but extracted scripts, native libraries and other files may still be unsafe if opened with another program. Do not execute unknown content, keep the archive separate from important folders, and inspect only software you trust or are authorized to analyze.

JAR extraction FAQ

Does extracting a JAR run the Java application?

No. Extraction reads archive entries and saves them as files. Running Java bytecode is a separate action that requires a compatible runtime.

Will extraction damage the original JAR?

Normal extraction reads the archive and writes a separate copy of its contents. Keep the original file until you verify the result.

Can I extract only MANIFEST.MF?

Yes. Browse to META-INF/MANIFEST.MF and select that entry, or use the desktop jar command with its stored path.

Why is the extracted folder larger than the JAR?

Many entries are compressed inside the archive. Their combined uncompressed size can be significantly larger than the JAR file itself.

Can I turn the extracted folder back into a working JAR?

Repackaging is possible with appropriate tools, but a working result may depend on the correct manifest, signatures, compression layout and build process. Editing a signed JAR usually invalidates its signatures.

Technical source

Archive and extraction behavior follows Oracle's JDK 26 jar command documentation and JAR File Specification. Last reviewed August 14, 2026.