JAR Jar File Opener Online JAR Viewer & Extractor Download Android App

100% local browser tool

Open and explore JAR files online

View MANIFEST.MF, browse contents, preview files, inspect CLASS files, and extract resources — all in your browser.

✓ No upload ✓ Free to use ✓ Works in browser
JAR

Drag & drop your JAR file here

or

Your file is processed locally. Nothing is uploaded.
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100% Private

Your JAR files are processed locally in your browser. We never upload or store your files.

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MANIFEST.MF Viewer

Quickly check Main-Class, Created-By, Manifest-Version and other manifest metadata.

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Browse & Extract

Explore folders, preview supported files and download selected files from the JAR archive.

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CLASS File Support

Inspect CLASS files with Hex view. Use the Android app for CLASS decompilation to Java.

Online JAR File Opener

Jar File Opener Online helps you open JAR files directly in your browser. A JAR file is a Java archive, usually a ZIP-based package that may contain Java CLASS files, resources, images, configuration files, and a metadata file called MANIFEST.MF.

This web tool is designed for quick inspection. You can select a local JAR file, browse its internal folders, view supported text files, inspect binary files in Hex view, and extract files without uploading anything to a server.

How to open a JAR file online

  1. Click Choose JAR File or drag a JAR file into the upload box.
  2. The tool reads the archive locally in your browser.
  3. Use the file browser to open META-INF/MANIFEST.MF, CLASS files, text files, and resources.
  4. Download selected files or export the archive contents.

What can this tool inspect?

  • JAR file name, size, total entries, and manifest status
  • MANIFEST.MF fields such as Main-Class and Created-By
  • Folder structure and archive contents
  • Text files such as XML, JSON, properties, MF, Java, and TXT files
  • CLASS files through Hex view

Can it decompile CLASS files?

The first web version focuses on safe local viewing and extraction. It can detect CLASS files and show Hex view. For CLASS decompilation to Java source code, use the Android version of Jar File Opener, which provides stronger offline file inspection features on your device.

Need JAR tools on Android?

Download Jar File Opener for Android to inspect JAR files on your phone, view CLASS files, and decompile supported CLASS files to Java.

Download Android App
How to Open JAR Files on AndroidUse the Android app to inspect JAR archives on your phone. How to View MANIFEST.MFCheck Main-Class, Created-By, and JAR metadata. How to Decompile CLASS FilesUnderstand CLASS decompilation and safe usage. How to Extract JAR FilesExtract resources, text files, and archive contents.

Important Notice

This tool is designed for opening and inspecting JAR files you own or have permission to access. Please respect software licenses, copyrights and developer terms. Online decompilation is not included in this web version.

FAQ

Are my JAR files uploaded?

No. This tool uses browser JavaScript to read your JAR file locally. Your file does not leave your device.

Can this website decompile CLASS files to Java?

The first web version supports CLASS file detection and Hex view. For CLASS decompilation to Java, download the Android app.

Can I open JAR files on Android?

Yes. Use the Jar File Opener Android app from Google Play for a better mobile experience.