How To Run & Open A JAR File (.JAR File Opener)

This Tutorial Explains What is a JAR File and How to Run and Open it in Windows, MAC, Linux using .JAR File Openers:

You must have come across JAR files at some point while surfing the Internet and must have wondered about it, about what it is and what it does. Here, in this tutorial, we will tell you everything about .JAR files, what they are, what they do, and how to open them.

You can use decompression if you want to view the files in the JAR, and if you want to run it, you will need the Java Runtime Environment. There are also some JAR file opener tools like File Viewer Plus, WinZip, 7-Zip, WinRAR, etc.

How to Open a JAR File

What Is A JAR File

JAR files

JAR is the abbreviation for Java Archive files. As the name says, it is an archive file. The archive file is a single file that has other files packed together to decrease storage space, probability of error, and many similar reasons. They are very much like ZIP files, the only difference being that it is used by the Java Runtime Environment.

The manifest in JAR files is their unique feature. A manifest is a special metafile that controls the behavior of JAR along with containing the information about the files within the file like compiled Java code, also called CLASS files, security certificates, image files, audio files, etc.

Runtime Environment can read and run the JAR file as a single request. It could be a browser add-on, a game, an application theme, and whatnot. It can be used for many purposes on mobile and desktop both. And since it contains thousands of files in a compressed format, you can easily move and share them.

How To Open JAR Files

Decompression (View Files)

Decompression

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If you want to view each file in a non-executable jar file, you can do that with the help of a JAR file compatible compression/decompression software. Either WinRAR or 7-ZIP, any one of them is a good choice. After you have installed WinRAR or 7-ZIP, run it, open the file, and extract files in it.

extract files

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Once you have extracted them, you can click on the files to view them. Although most files are usually a simple text file, you might need additional software to view some.

If you want the programs like 7-Zip or WinRAR to be the default programs for opening these files, right-click on the file, go to the ‘Open With’ option and then pick the default program. Click the browse button in the ‘Open With’ window to launch the File Explorer window. Then, find the .exe file for the software program you want as the default program for opening these files.

Java Runtime Environment (To Run The file)

Java Runtime Environment

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If you want to run the JAR file, you will need the Java Runtime Environment. If you have the Java Runtime Environment, then all you need to do is to double click on the file name. But it will only work if that particular file is executable. If not, you can just view the files in it.

If the file doesn’t run by double-clicking on it, chances are, it is not an executable file. And if your file is using an archive program like 7-ZIP, or WinRAR but you want to open them with Java, follow these steps:

  • Right-click on the file.
  • Select ‘Open With’.
  • Go to Browse for opening the File Explorer window.
  • Find the Java.exe file on your hard drive which is usually located within a subfolder under “Program Files (x86)\Java” folder or “Program Files\Java” folder.
  • Once you have found the file, select it and click Ok.

Programs To Open .JAR Files In Windows

#1) File Viewer Plus

File Viewer Plus

File Viewer Plus is a universal file opener compatible with Windows with which you can convert, save, view, and edit files. You can open more than 300 different types of files. You can play many multimedia formats, edit and save images and documents, convert files in batches to many file formats, and inspect the contents of a file with the help of this program.

Follow these steps to Open .JAR using File Viewer Plus:

  • Download and install the File Viewer Plus.
  • Launch the app on your Windows device.
  • Go to File and select the file you want to open.
  • Click on Start.
  • When the app is done, you will be able to see File information and Archive Metadata on the left and contents on the right-hand side screen.

Price: $58.94

Website: File Viewer Plus


#2) Corel WinZip 24

Corel WinZip 24

WinZip is one of the most used file compression utilities for Windows with which you can compress and decompress file archives along with creating backups for data and securely encrypting data. Compressing files saves storage space and can quickly transfer the files over the Internet.

Follow these steps to open a JAR file using Corel WinZip 24:

  • Download and Install Corel WinZip 24.
  • Find the file you want to open and right-click on it.
  • Go to Open With and select Winzip.
  • A new window will open with all the files in the selected file.
  • Extract the ones you want and then drag and drop them out of Winzip to wherever you want to save them.

Price:

  • WinZip Standard: $35.34
  • WinZip Pro: $58.94
  • WinZip Pro Combo: $58.94

Website: Corel WinZip 24


#3) 7-Zip

7-Zip

7-Zip is an open-source application that is widely used for archiving and compressing data. You can combine many files into an archive or just compress them to reduce the file size for saving storage space or enabling a quick file transfer.

Follow these steps to open a .JAR file with 7-Zip:

  • Download and Install Corel 7-Zip
  • Find the file you want to open and right-click on it.
  • Go to Open With and select 7-Zip.
  • It will extract the JAR files.
  • Once the files are extracted, you can view them by double-clicking on it.

Price: Free

Website: 7-Zip


#4) RARLAB WinRAR

RARLAB WinRAR

With RARLAB WinRAR file archiving utility, you can encrypt, compress, package, and back up your files. Although it is only available for Windows, you can also run it on Linux and macOS using Wine or similar compatibility layer applications.

Follow these steps to open a .JAR file with WinRAR:

  • Download and install RARLAB WinRAR.
  • Launch it to run the program.
  • Click on File and then select Open Archive.
  • Navigate to where the file is and select it.
  • Click on Extract To and go to commands.
  • Select “Extract to the specified folder.”
  • Accept defaults.
  • Select Display to decompress files.

Price: Free

Website: RARLAB WinRAR


JAR File Openers For Mac

#1) Corel WinZip Mac 7

Corel WinZip Mac 7

Corel WinZip Mac 7 is the OS X version of WinZip that allows you to compress and decompress file archives quickly using the drag-and-drop tools. It supports various compression formats and is used mainly to create .ZIP and .ZIPX archives. You can conveniently back up your files by creating data backup files and save them on a CD or DVD with the help of Zip and CD burning tool.

Follow these steps to open a JAR file using Corel WinZip Mac 7:

  • Download and install Winzip.
  • Launch the program by double-clicking on it.
  • Go to File and select Open Archive.
  • Browse to where the file is and select Open.
  • Click on Extract and accept the defaults or you can change the directory for decompressing the files.
  • Click Extract to finish.

Price:

  • WinZip Standard: $35.34
  • WinZip Pro: $58.94
  • WinZip Pro Combo: $58.94

Website: Corel WinZip Mac 7

You can also use any web browser for opening the JAR files for Windows, Mac, Linux, and Android along with Oracle Java Runtime Environment.

How To Run JAR In Windows 10

Follow these steps:

  • Get your system updated with the latest Java Runtime Environment.
  • Go to the folder of Java installation, right-click on the .exe file and run it as Administrator.
  • Press together Windows and X keys.
  • Select “Command Prompt or Powershell, both Admin.
  • Type cmd.
  • Type C:\Program Files\ followed by your Java installation folder.
  • Now try to launch the file. The file should open.

However, if you are still not able to Run JAR on Windows 10, you might need to change the registry a bit.

  • Right-click on the start button and select search.
  • Search for “Regedit” and open it.
  • Click on the HKEY_CLASSES_ROOT folder to expand it.

HKEY_CLASSES_ROOT

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  • Find jar_auto_file and jarfileterm folders.
  • Expand both the folders to find jar_auto_file > Shell > Open > Command.
  • Search for “Default”, right-click on it and select Modify.
  • In the value data type C:\Program Files\ followed by your Java installation folder.

jarfileterm folders

  • Click OK
  • When you have done the same with both the files, exit Regedit and launch JAR files.

How To Open JAR File Without JRE

JAR is a Java application and every Java application needs either a Java Virtual Machine or Java Runtime Environment. But not everyone has them.

So, if JRE isn’t installed in your system, here’s what you can do:

  • Use any open source installer generator in Java that runs without JVM.
  • The installer will generate a .exe file from .jar and will bundle the JRE with the app.
  • Now, you will need to run the file through a batch file. For that, create a new folder.
  • Put the .exe JAR and the JRE folder in that folder.
  • Next, you will have to create a batch file in the same folder. To create a batch file, open the Notepad or Wordpad, and type @echo [off]. In the next line add the title of your batch script and add echo with the first line. In the next line, type Pause. Save the file with .bat extension.

test_batch_file_notepad_670

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  • Lastly, add the code – jre\bin\java.exe -jar installer.jar to the batch file and save it.

This way, you will be able to execute the file through the .exe file and batch file.

How To Run A JAR File In Linux

If you have Java installed on your Linux, you will be able to run the JAR file with a double-click or picking option from right-click. You only need Java Runtime Environment and you will be able to easily run the file in Linux. However, sometimes it is not that easy, even with Java installed, you get an error message.

run_java_jar_error

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You will get the error something like what is shown in the above image.

To fix this error,

  • Right-click on the JAR file.
  • Open properties.
  • Go to the permissions tab.
  • Check the box beside ‘Allow executing this file as program’.

Now, with just double-click, the file will run without any problem. However, if you are still not able to run the file, here’s what you can do:

  • Right-click on the JAR file.
  • Go to “Open With Other Applications”.
  • Select Show other applications.
  • Select Open With OpenJDK Java X Runtime.
  • If you don’t find the Java option, install JRE.

You should be able to run the file successfully now.

How To Open Jar Files Online

There are many tools available online that you can use to open the JAR files.

  • Select one of the tools and open it in your browser.
  • Go to select files and select the file you want to open.
  • Click on the extract option to get the list of contents in the JAR archive.
  • Click save and select the location to save the extracted files.

The options might vary with the online tool you want to use, so pick accordingly.

Suggested reading => How to open XML files online.

Errors In Opening JAR Files

Errors in JAR Files

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It is not rare to see errors when trying to access Java applications. The errors could be due to the security settings in the Windows operating system. You might encounter error messages like blocked Java Application, or an untrusted application is blocked from running by your security settings. But you can fix these issues by fixing the security level in the Java control panel applet.

First, make sure Java is enabled in your browser. You can learn how to enable Java in your browser here. Set up the control panel properly for using Java, otherwise, you might not be able to open Java applets even after you have installed JRE. And make sure you restart the browser after enabling Java in your browser. And also ensure that you are running Java’s latest version.

Content settings

Sometimes, when Windows doesn’t know what to do with the JAR file, it tries to open it in a program that doesn’t support the format. In that case, right-click on the file, select open with and choose the app that is suitable for opening the JAR file.

To run it directly in the Java Runtime Environment, go to program files and click on the Java folder. Then go to jre1.8.0_211 and open the bin to select java.exe.

open-with-java

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If it shows a security error while opening, go to the start menu and type configure Java in the search tab. It will open the Java Control Panel. Navigate to the security tab and check the box beside “enable Java content for browser and web start application”. Change the security level to high and if needed, add to the exception site list. Click on OK.

Converting A JAR File

Converting A JAR File

You can decompile the CLASS files of Java files using the Java decompilers. All you have to do is upload the file and pick the decompiler you want to use.

To use the Java application on the Android platform, you will need to convert a Java application and that will need JAR to APK file conversion. You can run the file in an Android emulator so that it automatically creates an APK file. But the easiest way is to get a Java program on Android just by compiling the APK from the original source code.

You can use programming applications like Eclipse to make executable JAR files. But you can’t convert a JAR file directly to a Java Web Archive file or WAR file. It is because WAR files have a particular structure that is not present in JAR files. Instead, what you can do is add the file into the lib directory after building a WAR, this will make the components inside the JAR files available for use.

You can watch the video here about how to convert the JAR file.

It is easy to rename the file extension from .JAR to .ZIP and easier to make a ZIP file from a JAR file. The file doesn’t actually convert but it allows programs like 7-Zip or PeaZip or similar programs to open the JAR file easily.

FAQs For Opening A JAR File

Q #1) Why can’t I open my JAR file?

Answer: Try updating or reinstalling your Java Runtime Environment and if you still can’t open it, maybe that file isn’t meant to open or tamper with.

Q #2) Are JAR files executable?

Answer: Not all JAR files are executable. But some often contains a runnable software or source code that can be made executable.

Q #3) How is the JAR file different from the executable JAR file?

Answer: JAR file is a blend of compiled Java classes while executable JAR files are also the same but with Main class.

Q #4) What is a manifest file in a JAR?

Answer: MANIFEST is the manifest file in JAR and you can find it under the META-INF directory. It contains a simple list of pairs of keys and values, grouped into sections and are called attributes or headers.

Conclusion

This tutorial explains what .JAR file extension is and how to open it. And if you encounter an error while opening the .JAR file, the above-mentioned steps will help you deal with them. There are so many programs that can help you open a JAR file and converting them isn’t too difficult as well.

Coral WinZip is the best option for opening the JAR file since it is available for almost all platforms and is easy to use. You can also use WinRAR or 7-Zip if you have them pre-installed on your system.

Suggested reading =>> How to open a JNLP file