You may have encountered archives before. A common archive file type is ZIP file. Another type of archive you may come across is a JAR file. We will take a look at what this file is and the best applications to open JAR files on Windows.
Archive files such as ZIP files and JAR files provide a way to pack multiple files into a single file, reducing the amount of space required to store them. JAR stands for Java ArChives. It’s a package file format used to combine multiple Java class files and their related resources such as text and images into a single file.

Indeed, JAR files were originally developed so that end users could download Java applications and their components in a single HTTP request.
If you try to open a JAR file without installing a compatible program that can open that file type, you may get a “Cannot access JAR file” error. In that case, try one of the applications below to open the JAR file on your Windows computer.
JAR files can be opened in two ways:
- Open and browse file contents
- Run JAR file in Java (executable)
We will review applications to help you browse and check the contents of JAR files.
Table of Contents
Application to open JAR files on Windows
There are several programs you can use to browse and view JAR file contents on a Windows computer. We will go over a few of them. You may even find that you already have an application capable of opening JAR files on your computer.
1. WinRar

WinRar is shareware which you can download and run for free, but it will constantly prompt you to purchase a license. In any case, Download WinRar, install it and use it to open the JAR file. Once you have opened the JAR file with WinRar, you can extract its contents.
2. 7-Zip

Similar to WinRar, 7-Zip is an archive viewer and decompressor that you can use to open JAR files. Unlike WinRar, 7-Zip is free and open source. Download for Windows here. Once the installation is done, you can open the JAR file, extract it, and view the files in the archive. Just right click on the JAR file, select Open with and choose 7-Zip File Manager.

If you don’t see an option to open the file with 7-Zip File Manager, select Choose another app and select 7-Zip File Manager from the list:

Choose Always use this app to open .jar . files option to set 7-Zip as default JAR file viewer.
Application to open JAR files online
When all else fails, you can always use an online tool to open the JAR file. There are several to choose from. All the online tools listed below allow you to drop the JAR file onto the website and download the content. This is a good option if you don’t come across these repositories often and don’t want to install new software.
3. Online archive decompression tool

The Online Archive Extractor is a browser-based tool that you can use to decompress several types of archives, including JAR files. The site is secure, and since the tool works locally inside the browser (i.e. not server-side), you can rest assured that your files won’t be sent over the internet. You will also find that decompressing JAR files with the Online Archive Extractor is faster than with some other archive extractors because almost no data is transferred online.
4. AppsCMS JAR file opener

JAR File Opener from AppsCMS works a little differently than Online Archive File Extractor. It transfers your files to its servers. However, they assure users that “We only archive your Jar files for a very short time to extract the contents and then delete the files. We do not store any of your JARs or the content in your JARs. Since it’s also online, this option will also work for opening JAR files on Mac, Linux, Ubuntu, and all versions of Windows.
5. Online Java Compiler

Online Java Compiler provided by Leonardo Santos of Brazil. His tool decompiles .jar and .class files online. It’s a simple tool that does exactly what it says it does. Most of the files you extract from a JAR file will be text files, but some may be other file types that require an additional application to view them.
6. EzyZip .’s Jar Extraction File Tool

EzyZip’s Jar Extract File Tool has more bells and whistles than other online JAR file openers. Some files extracted with the tool can be previewed in the browser, and you also have the option to save multiple files and folders to a destination folder of your choice at once.
7. FreeFileConvert

The last item on our list is a little different from the others. The JAR to ZIP Converter from FreeFileConvert converts your JAR file into a ZIP file that you can open natively in Windows. The JAR file you want to convert can be on your computer or in a cloud service like Google Drive or Dropbox. Alternatively, if you have the URL of the JAR file, you can enter it and use this tool to convert it to a ZIP file.
Run JAR file with Java runtime environment
So far, we have discussed the ways watching JAR file. If you want run those files, you will need to use the Java Runtime Environment. Check out our article on how to run a JAR file on Windows to learn how to install Java on your computer and run JAR files in the Java Runtime Environment.