Eclipse startup is controlled by the options in
$ECLIPSE_HOME is not defined, the default
eclipse.ini in your Eclipse installation directory (or in the case of Mac, the
Eclipse.app/Contents/MacOS directory) is used.
eclipse.ini is a text file containing command-line options that are added to the command line used when Eclipse is started up. There are many options available, please see here.
- You can, and should, experiment with changes to the launch command from your Command Prompt/Terminal before changing the
- Each option and each argument to an option must be on its own line.
- All lines after
-vmargsare passed as arguments to the JVM, so all arguments and options for eclipse must be specified before
-vmargs(just like when you use arguments on the command-line)
- Any use of
-vmargson the command-line replaces all
-vmargssettings in the .ini file unless
--launcher.appendVmargsis specified either in the .ini file or on the command-line. (doc)
- Make a backup--keep a copy of the original contents on hand so you don't break your installation and have to download it all again.
eclipse.ini looks something like this (the exact contents will vary based on operating system and which Eclipse package you have):
-startup ../../../plugins/org.eclipse.equinox.launcher_1.2.0.v20110502.jar --launcher.library ../../../plugins/org.eclipse.equinox.launcher.cocoa.macosx.x86_64_1.1.100.v20110502 -product org.eclipse.epp.package.jee.product --launcher.defaultAction openFile -showsplash org.eclipse.platform --launcher.XXMaxPermSize 256m --launcher.defaultAction openFile -vmargs -Dosgi.requiredJavaVersion=1.5 -XX:MaxPermSize=256m -Xms40m -Xmx512m
Among other things, this sets the heap space to 40MB initially and a maximum of 512MB, and also specifies a maximum PermGen size of 256MB. A max heap of 512MB might be OK for some users, but it's often necessary to bump that value up for large project sets or when some third-party plugins are installed.
Specifying the JVM
One of the most recommended options to use is to specify a specific JVM for Eclipse to run on. Doing this ensures that you are absolutely certain which JVM Eclipse will run in and insulates you from system changes that can alter the "default" JVM for your system. Many a user has been tripped up because they thought they knew what JVM would be used by default, but they thought wrong. eclipse.ini lets you be CERTAIN.
The following examples of
eclipse.ini demonstrate correct usage of the -vm option.
Note the format of the
-vm option - it is important to be exact:
-vmoption and its value (the path) must be on separate lines.
- The value must be the full absolute or relative path to the Java executable, not just to the Java home directory.
-vmoption must occur after the other Eclipse-specific options (such as
--launcher.*, etc), but before the
-vmargsoption, since everything after
-vmargsis passed directly to the JVM.
- For the 32-bit Eclipse executable (eclipse.exe on Windows) a 32-bit JVM must be used and for the 64-bit Eclipse executable a 64-bit JVM must be used. 32-bit Eclipse will not work with a 64-bit JVM.
Here is an example of what
eclipse.ini might look like on a Windows system after you've added the
-vm argument and increased the maximum heap space:
-startup plugins/org.eclipse.equinox.launcher_1.2.0.v20110502.jar --launcher.library plugins/org.eclipse.equinox.launcher.win32.win32.x86_1.1.100.v20110502 -product org.eclipse.epp.package.java.product --launcher.defaultAction openFile --launcher.XXMaxPermSize 256M -showsplash org.eclipse.platform --launcher.XXMaxPermSize 256m --launcher.defaultAction openFile -vm C:\Java\JDK\1.8\bin\javaw.exe -vmargs -Dosgi.requiredJavaVersion=1.5 -Xms40m -Xmx1024m
Remember that the exact values will differ slightly depending on operating system and Eclipse package.
-vm value: Windows Example
This is how the
-vm argument might look on Windows (your exact path to
javaw.exe could be different, of course):
An alternative way is to insert the following VM option before the -vmargs option in the Eclipse shortcut properties(edit the field Target inside the "Shortcut" tab):
This might not work on all systems. If you encounter "Java was started but returned exit code=1" error while starting the eclipse, modify the
-vm argument to point to
jvm.dll (exact path could be different):
-vm value: Linux Example
This is how the -vm argument might look on Linux (your exact path to
java could be different, of course):
-vm value: Mac OS X Example
On a Mac OS X system, you can find
eclipse.ini by right-clicking (or Ctrl+click) on the Eclipse executable in Finder, choose Show Package Contents, and then locate
eclipse.ini in the
Eclipse folder under
For versions of Mac OS X 10.7+ the location is something like
For example, the latest JDK 1.8 (as of July 2015) is
Perhaps the best way to determine the location for the JDK you want to use is with the utility
From the list produced by that command, select the JDK you want to use and put that path into the eclipse.ini file, making sure to append
/bin/java to the path (eg,
Note that the full path can either include
java or not. For example, the following will both work:
- FAQ How do I run Eclipse?
- FAQ How do I increase the heap size available to Eclipse?
- FAQ How do I increase the permgen size available to Eclipse?
This FAQ was originally published in Official Eclipse 3.0 FAQs. Copyright 2004, Pearson Education, Inc. All rights reserved. This text is made available here under the terms of the Eclipse Public License v1.0.