How To Open JNLP File On Windows 10 And macOS

This tutorial explains what is JNLP File and how to open it on macOS, Windows 10, other Windows versions, and using Chrome and Firefox:

Every file on your system is associated with an application that it runs on. Java Network Launch Protocol or JNLP is no exception. But sometimes you might find it hard to open a JNLP file.

These files are used on a remote desktop client for launching applications from a hosted web server. Java Web Start application, Java Plug-in, and similar programs are run on JNLP files.

How to Open a JNLP File

What Is JNLP File

The JNLP or Java Network Launch Protocol files are program-specific. Sometimes, your system might not recognize JNLP files properly for executing them with the Java Web Start application.

In such cases, you will have to modify the file association of your computer to correctly open the JNLP files with the Java Web Start application.

How To Open JNLP File

#1) Install JAVA’s Latest Version

Install JAVA’s Latest Version

Editing the file association of your system is one way of opening a JNLP file correctly. But before you get into that, you must make sure that you have proper Java programs on your system.

Search for a Java program on your system. If you don’t find it, then it means that it is not yet installed. In that case, download the latest version of Java on your system.

To do that

Java Download

  • You will be taken to the appropriate download page. Click on Agree and start the free download button.
  • This will start the download.

After the download is complete, click the install launcher to complete the installation.

Recommended reading =>> How to download and install Java

#2) Editing File Association

Worrying about how to open the JNLP file? As mentioned above, every file type is associated with an application it runs on.  JNLP files are run by Java Web Start and sometimes, it is possible that the JNLP files can become associated with other applications, thereby making them open incorrectly.

In such cases, you will need to modify the file association on your computer so that the JNLP files open with Java Web Start.

#1) Windows 10

  • Open Control Panel from the Start option.

Control Panel

  • Go to Programs and select Default Programs.
  • Click on ‘Associate a file type or protocol with a program’.

Associate a file type or protocol with a program

  • From the list of extensions, select JNLP.
  • Select Change Program.
  • If the proper Java application doesn’t show automatically, then choose the More Apps option.
  • Now look for another app on this PC.
  • Go to the Program Files (x86) folder.
  • Click on the Java folder.
  • Open the latest version of JRE you have.
  • Go to the bin folder.
  • Double-click on the javaws.exe application.

Open javaws.exe

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  • Click OK and then Close.

This is the process to open the JNLP file in Windows 10.

#2) On Mac

  • Go to the Finder.
  • Search for the JNLP file you want to open.

Select the JNLP file

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  • Right-click on the file.
  • Click on Get-Info.

Get Info

  • On the information screen, go to Open With and click on the arrow next to it.
  • From the application list, select Java Web Start.

Spot light Comments

  • If you don’t find it in the options, then select Others and find it in the complete application list.
  • Select the right app and click on Change All to apply the change to all JNLP files.
  • Click Continue.

The JNLP files will now open on Mac without any issue.

#3) Windows 8

  • From the right edge of the screen swipe in, go to Search.

open search bar

  • Enter Default Programs in the search bar.

Default Programs

  • Now click on the option –  ‘Associate a file type or protocol with a program’.

Associate a file type or protocol with a program

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  • Under the registered file types list, find.JNLP.
  • Click on it once to highlight the file under the Extensions column.
  • Select Change Program.

change program

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  • From the list of programs, select Java Web Start Launcher.

Java Web Start Launcher

  • If it is not in the options, click on More Options, and then select Look for another app on this PC.
  • Double click on Local Disk (C:).

Local Drive

  • Double Click on Program Files (x86) or Program Files, whichever you see.

Program files

  • Select the Java folder.
  • Select the latest JRE folder.

Java folder

  • Select bin.
  • Click on javaws.exe and hit Open.

You will not have any more issues in opening the JNLP files on WIndows 8.

#4) Old Windows Versions

Windows 7 and Vista

  • Select Control Panel from the Start menu.
  • Select Category from the View By option on the top right corner of the control panel.

View by options

  • Go to the default programs option.
  • Click on the ‘Make a file type always open in a specific program’ option.

Control Panel Programs

  • Locate JNLP from the list of Extensions under the Name column and click on it to select it.

Select JNLP File

  • Select the Change option.
  • In the Open With window, select Browse.

Select Browse

  • The Open With dialogue box will take you to the c:\Program Files directory.
  • Now select the Java folder.

JNLP files

  • Double click on the latest JRE folder.

Double click on Jre folder

  • Double click the bin folder.

Double Click Bin folder

  • Now, double click the javaws application.

double click the javaws application

  • Click OK and then Close.

You should be able to open the file now.

For Windows 2000/XP

  • Go to the Start option.
  • From Settings, select Control Panel.

control panel

  • Go to Folder Options and click on it.

Folder Options

  • In the window that opens, click on the File Types tab.

File Types Tab

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  • Under the registered file types, locate JNLP and highlight the file by going to the Extensions column and clicking on the JNLP file once.
  • Hit the Change button.

Hit the Change Button

  • In the Open With window, click on Browse.
  • Locate the file javaws.exe from the Open With dialogue window.


  • Double click the Java folder in the C:\Program Files folder.
  • Now double click on the JRE folder.


  • Find the bin folder in it and double click on it.

Bin Folder

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  • Now select javaws.exe and click Open.


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  • Click Ok to close the window.
  • Click Apply and click OK.

You will be able to open the JNLP files now.

Configuring Chrome To Open JNLP Files

  1. Launch Chrome.
  2. Go to the website with a link to a JNLP file.
  3. Download the file. You will be able to see the file at the bottom window.
  4. Click on the arrow next to it and select ‘Always Open Files Of This Type’.
  5. When Chrome asks the program with which you want to open the file, select ‘Java Web Start Launcher’.
  6. If you don’t have Java Web Start Launcher, then download and install it.

Now you can open JNLP files on Chrome.

Firefox Displays JNLP Files As Text

Usually, as the browser or system is not properly set up to send JNLP files to Java Web Start, it will face certain issues while opening the file. These issues could be being unable to open the file at all or your browser ending up displaying it as text. So, to open the JNLP file on Firefox, make the following adjustments.

#1) On Linux

  • Launch Firefox and Press Alt.
  • Go to tools in Firefox.

Launch Firefox

  • Click on Options.

Select Tools

  • Scroll down the list and find the JNLP File.
  • Select Use Java Webstart Launcher in action.

#2) OSX

  • Download the JNLP file.
  • Go to Finder and find the file.
  • Right-click on it.
  • Select Get Info.
  • In the Open With, select Java Web start.

Java Web Start

  • If you can’t find it in the list, then navigate to System, go to Library and click on Core Services. Here, you will find Java Web start.
  • If it’s not there as well, then go to Applications and click on Utilities. There you can find Java Web start.

Frequently Asked Questions

Q #1) Why am I not able to launch JNLP?

Answer: Make sure you have the latest version of Java. Also, see that your browser isn’t blocking the file from an unidentified developer as it might lead them to block the file RCSB-ProteinWorkshop. jnlp. Always select the ‘Open Anyway’ option in such cases.

Q #2) How to start Java Web Start launcher?

Answer: Go to the control panel from start and double click on the icon of Java. It will launch the Java Control Panel. Go to the General Tab. From the Temporary Internet Files section, select View. Now, double click on the application you want to launch.

Q #3) I am getting a fatal initialization error while using the web start?

Answer: JNLP files need to be executed with javaws and if another application is your default java client, you will come across this error. To start the file, either change your default browser preferences so that the JNLP application opens with javaws, or go to the command line in javaws viewer to force the JNLP file to ec=xecute with Java.


JNLP files might cause problems if they are not updated or if the file associations are mixed up. So, it is easy to fix the issue when you are unable to open the JNLP file.

Further reading =>> Open Cal File using Cal File Viewer

However, try not to meddle with them as one wrong click or keystroke in your program could get messed up. So, unless necessary, let these files be.