Java Client

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Old School RuneScape
Old School RuneScape client icon (Windows).png
Developer Jagex Ltd.
Publisher Jagex
Engine RuneTek
Release dates 22 February 2013
Genre Fantasy MMORPG
Platforms Windows, Mac
  • 1.5 GHz Processor
  • 256 MB RAM
  • 128 MB 3D Graphics Card
Input Keyboard
Java Client
Old School RuneScape client icon (macOS).png
Developer Jagex Ltd.
Publisher Jagex
Engine RuneTek
Release dates 22 February 2013
Genre Fantasy MMORPG
Platforms Windows, Mac
  • CPU: Intel i3 or AMD (2.4GHz)
  • RAM: 4GB
Input Keyboard

The Java Client is the Old School RuneScape launcher built by Jagex for desktop platforms. In the past, the client was an alternative to playing the game in a browser. However, due to multiple browsers discontinuing support for Java applets , Jagex was forced to drop support for browser play. The client does not support Hardware acceleration, and is limited to 1 processor core and 50 frames per second.

The official Java client can be downloaded from the Download section of the Old School RuneScape website for Windows and macOS.

It is possible to run the Java client on Linux, although not officially supported. See Linux game installation guide for more information.

Editing the client's configuration[edit | edit source]

Windows[edit | edit source]

On Windows, the configuration is stored in the file %USERPROFILE%\jagexcache\jagexlauncher\oldschool\oldschool.prm

To edit this file, type %USERPROFILE%\jagexcache\jagexlauncher\oldschool into File Explorer's address bar and open oldschool.prm with Notepad. If you can't save, make sure the game is closed and try again.

macOS[edit | edit source]

On macOS, the configuration is stored in the file

To edit this file open Terminal and type the following:

open -a TextEdit /Applications/Old\ School\

Configuration options[edit | edit source]

Default configuration[edit | edit source]


Decreasing minimum heap usage[edit | edit source]

The initial release of the Java client did not include the -Xmx384m Java parameter. If you delete it, the client will default to the minimum which is the equivalent of -Xmx256m.

Warning: Lowering the amount of memory used by the Java client can cause game instability and increase lag.

Increasing maximum heap usage[edit | edit source]

You can increase the amount of maximum heap the Old School RuneScape client uses. This can help decrease lag.

To do this, change -Xmx384m to a higher value; -Xmx512m is recommended.

Warning: Allocating too much memory to the heap can cause game instability. If your client begins to crash to desktop after increasing the amount of maximum heap, decrease the maximum heap size and try again.

Using a different garbage collector[edit | edit source]

You can choose a different garbage collector for the Old School RuneScape client to use. This can improve map loading times and decrease lag caused by garbage collection.

To do this, make the following changes to the client's configuration file:

  • Remove the following flags
  • Add the following flags:

Changing the world the client connects to[edit | edit source]

Edit the flag adding the world you wish to connect to: -Dcom.jagex.config=

For example:

  • Old School (world 330): -Dcom.jagex.config=

Note: The world server number for some Old School RuneScape worlds does not match the actual world number. Hover over the world server links on World Servers List to find the correct number for the world you wish to connect to.

SSL connectivity[edit | edit source]

Enabling SSL connectivity can help decrease lag you if you're connecting via a mobile network, restrictive network, proxy, or firewall.

To do this, add one of the following flags to the configuration file:




Note: TLS 1.1 and 1.2 protocols are not available without the KB 314025 update on Windows 7. The use of SSLv3, TLSv1 and TLSv1.1 is not recommended unless your device does not support TLSv1.2 or you are experiencing connection issues.

Recommended configuration[edit | edit source]


Enable Dark Mode on macOS[edit | edit source]

On macOS Mojave and later, you can enable the system dark appearance by editing the Info.plist configuration file using Terminal. Close the game client, then copy and paste the following to a new Terminal Shell:

plutil -insert NSRequiresAquaSystemAppearance -bool NO /Applications/Old\ School\

This will append the NSRequiresAquaSystemAppearance key to the configuration file with a boolean value of NO. To revert changes, simply change the boolean value to YES.

Multiple client configuration[edit | edit source]

Old School RuneScape client icon (alternative).png
  1. Go to %USERPROFILE%\jagexcache\jagexlauncher
  2. Create a new folder and name it either "runescape" or "beta" for whichever version you'd like to create a client for.
  3. Copy the .prm file from %USERPROFILE%\jagexcache\jagexlauncher\oldschool
  4. Paste the .prm file inside the newly created folder named "classic" or "runescape" or "beta"
  5. Rename the file to match the folder; classic.prm or runescape.prm or beta.prm
  6. Open the renamed .prm file in Notepad.
  7. Remove the flag: -Dcom.jagex.config=
  8. Replace it with the corresponding flag:
    • Classic: -Dcom.jagex.config=
    • RuneScape: -Dcom.jagex.config=$(Language:0)/
    • DarkScape/Beta: -Dcom.jagex.config=
  9. Save and close the file.
  10. Locate the Game Client shortcut and make a copy of it; By default, the Game Client shortcut is found on your Desktop.
  11. Right-click the new shortcut copy, and select "Properties" from the context menu.
  12. Under the shortcut tab, find the box right of the word "Target"; It should display C:\Users\<user_name>\jagexcache\jagexlauncher\bin\JagexLauncher.exe oldschool
  13. Change the oldschool on the end to match the folder name created in step 2.
  14. Click OK to save the changes made.

Note: As of 17 December 2019, the Java Client can no longer be used to play other versions of the game like RuneScape Classic, RuneScape 3, DarkScape nor RuneScape Beta.[1] But you can follow a modification of these steps if you wish to create other shortcuts to launch instances of the game with different Java parameters for things like connecting to specific world servers.

Troubleshooting[edit | edit source]

Installation Issues[edit | edit source]

Unable to load Java Runtime Environment (macOS)[edit | edit source]

This error indicates you do not have a suitable version of Java installed on your system.

To install the Java Runtime Environment, please visit

If you receive an error when installing Java, see the Re-install Java support article.

To install the game client:

  • Double click .dmg to make its content available
  • Drag the application from the .dmg window into /Applications to install (may require administrator password)
  • Wait until complete
  • Eject the .dmg (by clicking Eject button)

Error applying transforms[edit | edit source]

This error indicates you are unable to install the Java client because your computer's language is not English. To fix this, switch your computer's language to English.

Unable to load parameter[edit | edit source]

This error means the shortcut you use to launch the game is having a problem.

  1. Right click shortcut
  2. Properties
  3. Target
  4. Edit target parameter to match:

C:\Users\<user_name>\jagexcache\jagexlauncher\bin\JagexLauncher.exe oldschool

Connection Issues[edit | edit source]

Set up exceptions to your firewall for RuneScape[edit | edit source]

  • Some security programs including 360, Avast, AVG, Avira, Bitdefender, BullGuard, K9 Web Protection, McAfee and Outpost have blocked or interfered with Java-based applications like RuneScape in the past. If you're getting a firewall error, make sure you have added exceptions for: Java.exe JagexLauncher.exe * oldschool* For instructions on how to do this check your antivirus/firewall software's website.
  • On your router, you would need to open the following ports: 443, 43594 and 43595 This will vary depending on your make and model of router, and instruction booklets are often included with your router or can be found on the manufacturers website. You can also find information on How to Forward a Port

Unable to create advertising[edit | edit source]

  • You might see this error if you attempt to launch 3 or more instances of the Java client. The only known work-around is to click the shortcut to launch the game client a bunch of times really quickly in order to launch more instances of the client.
  • If you're seeing this error and you have only launched 1 instance of the client, that means your game cache is corrupted and you will need to restart your computer and clear the game cache.

Login limit exceeded. Too many connections from your address.[edit | edit source]

  • You might see this error if you attempt to connect with more than 10 accounts from the same computer at the same time. The only known work-around is to use VPN tunneling.

Unable to connect[edit | edit source]

  • You might be having a connection problem to one or more world servers. Try connecting from the OSRS website's World Servers List instead of by launching the client. This has been known to solve connection issues with the Mobile client in the past.

Too many login attempts from your address. Please wait a few minutes before trying again.[edit | edit source]

  • This is a known issue some players are currently experiencing either because of a connection error or someone is attempting to brute force into their account.
  • If you can login to another account, your account is temporary locked and you should change your password.
  • If you can't login to another account, you most likely have a connection error and you might be able to login by using a mobile connection or VPN.
  • This error typically goes away on its own if you wait about 30 minutes before trying to login again, but attempting to login many times can make it worse.
  • If it happened to you, report it to Jagex.

Performance Issues[edit | edit source]

No sound[edit | edit source]

  • Make sure your sound isn't muted.
  • Make sure your sound output is configured to the correct speakers/headphones.
  • Make sure you hear other sounds coming out of your computer. You can test by playing a song or video.
  • Raise your volume to make sure it's at 100% and check that it is also at 100% on your Volume mixer by right clicking the Sound icon on your tray menu.
  • If you still don't hear any sound, clear your game cache.
  • If you still don't hear any sound, try enabling SSL connectivity.

Black screen[edit | edit source]

  • This can be caused by a connection issue, but most of the time it's caused by a corruption of your game cache.
  • Try clearing your game cache and flushing your local dns cache.

Graphical bugs[edit | edit source]

Clear the game cache[edit | edit source]

The quickest way which works most of the time to delete the game cache is to go to %USERPROFILE%\jagexcache\oldschool\LIVE and delete:

  • preferences.dat
  • preferences2.dat

The game cache should rebuild itself.

Sometimes multiple instances of the game cache get created as a result of a corruption of the Jagex files. If this happened, you will need to manually delete all of these files and folders:


Warning: Do not delete the %USERPROFILE%\jagexcache folder because the Java client files get stored under C:\Users\<user_name>\jagexcache\jagexlauncher

If you deleted this folder while having the Java client installed, that can create a registry error.

If you're unable to re-install the Java client after doing this, you can try uninstalling the Java client, deleting all Jagex files and using CCleaner to clean your registry.

deletecache.bat[edit | edit source]

This command prompt script for Windows was written by Pescao6 to assist players with deleting all Jagex cache files quickly.

Disclaimer: This software is provided "as is" without warranty of any kind. You may use this software at your own risk.

Copy and paste the following into a WYSIWYG text editor (e.g. Notepad) and save it as a file named deletecache.bat:

@echo off
echo Press ENTER to delete the Java and Jagex cache...
rd /s /q %HOMEDRIVE%\.jagex_cache_32
rd /s /q %WINDIR%\.jagex_cache_32
rd /s /q %USERPROFILE%\AppData\LocalLow\Sun\Java
rd /s /q %USERPROFILE%\.jagex_cache_32
rd /s /q %USERPROFILE%\jagexcache\jagexlauncher\bin\.jagex_cache_32
rd /s /q %USERPROFILE%\jagexcache\runescape
rd /s /q %USERPROFILE%\jagexcache\oldschool
rd /s /q %USERPROFILE%\jagexcache1
rd /s /q %USERPROFILE%\jagexcache2
rd /s /q %USERPROFILE%\jagexcache\speccollect
del /q %USERPROFILE%\jagex_cl_oldschool_LIVE*.dat
del /q %USERPROFILE%\jagex_cl_runescape_LIVE*.dat
del /q %USERPROFILE%\jagex_cl_runescape_LIVE_BETA*.dat
del /q %USERPROFILE%\jagex_cl_speccollect_LIVE.dat
del /q %USERPROFILE%\jagexappletviewer.preferences
echo Completed succesfully! All existing Java and Jagex cache files were deleted.

Restart your computer to make sure no Jagex files are being used, right click the deletecache.bat file, and run it as an administrator.

Official changelog[edit | edit source]

  • 1.0.0 - Initial release.
  • 1.0.1 - Fixed bug where Vista and 7 users need to disable UAC to be able to install client, added an options bar with a language setting on top.
  • 1.0.2 - Uses its own interface instead of the default Windows style for the language setting. Client automatically removes the languages menu and copyright notification upon log in.
  • 1.0.4 - Client scrollbar changed.
  • 1.1.0 - Client update on 17 October.
  • 1.2.0 - Possibly unsuccessful attempt to remedy lag problems after the bot nuke event.
  • 1.2.3 - Fixed the removal of the languages menu and copyright notifications when logging in on Linux and Mac, plus providing a direct link for the jagexappletviewer.jar for use by custom clients like the RSU-Client and other Linux Clients.
  • 1.2.4 - The client may now be launched directly from the website.[2]
  • 1.2.5 - Added support for the Local timestamps in chat box Interface setting.
  • 1.2.6 - Fixed an issue that prevented use on mobile networks.
  • 1.2.7 - Fixed scrollbars in adverts.

References[edit | edit source]

  1. ^ The RuneScape Team. "The future of RuneScape technology". 07 November 2019. Old School RuneScape News.
  2. ^ Mod Rascasse. PSA: Google Chrome will no longer support Java meaning no Runescape.. reddit. 30 March 2015.*