JDownloader is slow

JDownloader is slow

This is a troubleshooting guide for whenever your JDownloader is slow.
This article is not about slow download speed! Read this article if you are dealing with slow download speeds.

1. Check if the issue is in any way related to your downloadlist/linkgrabber list or settings
   a. Close JD and create a backup of all of your settings and downloadlist.
   b. Rename/delete your current config folder.
   c. Start JD and check if it runs faster.
   If there is no difference at all, jump to the last point of this guide else just rollback your config and continue with the next steps to cleanup your downloadlist/linkgrabber list.
2. Huge download list or linkgrabber list?
   If your downloadlist contains a significant amount of items you may want to delete some items.
3. Huge linkgrabber list due to forgotten deselected or filtered elements?
   Switch to the linkgrabber tab and check the right side.
   If you see unchecked checkboxes, check them to be able to see see- and manually delete the hidden items.
   You may also just delete all items at once by clicking on the yellow arrow in the bottom toolbar:
   
   If you've used custom LinkGrabber filters your linkgrabber may also contain a lot of such filtered items which you can see in the bottom toolbar:
   
4. If none of the above has helped and/or for some reason you permanently need to keep a lot of items in your LinkGrabber/Downloadlist, you might be running into memory issues.
   In this case continue reading and follow the steps down below.

JDownloader is freezes or is slow due to JVM running out of memory

Only follow these steps if none of the others have helped you to solve your problem!

Preamble:

JDownloader is written in Java and thus is running in the JVM (Java Virtual Machine).
This JVM can run out of memory even if your OS is currently having more than enough free RAM.
You can check the RAM usage under Settings -> Help -> Memory
Screenshot:

The reason of JDownloader running out of memory include:

• Bad .vmoptions configuration file with too low max allowed memory value (we will come back to this later)
• 32bit Java on 64bit OS
• Old JDownloader installation running on a 64bit system using a 32bit Java due to us delivering it with JDownloader back then

Possible solutions:

Option 1 - the easy way:

1. Close JDownloader and backup your JD configuration, see Configuration Backup & Restore help article
2. Uninstall JDownloader.
3. Obtain the new JDownloader installer (on Windows, please prefer correct bitness) and re-install JDownloader.
4. Restore your old JD configuration as explained in the linked Backup & Restore article in step 1.
5. The problem should be gone now.

Option 2 - for advanced users:

1. Close JDownloader, create a backup of your old .vmoptions file if existent and edit your .vmoptions configuration file to allow JVM to use more memory.
2. Restart JDownloader - the problem should be gone.

Tags: java.lang.OutOfMemoryError: GC overhead limit exceeded, memory, RAM, freeze, freezes, freezing