# Assigning the default JRE for the workbench

The default JRE is used for compiling and launching Java programs in all projects unless you specifically override the default JRE on a project's build path or on a launch configuration.

Here is how you can change the default JRE:

1. Open the Java > Installed JREs preference page.
2. Check the box on the line for the JRE that you want to assign as the default JRE in your workbench. If the JRE you want to assign as the default does not appear in the list, you must add it.
3. Click OK.

Note: Changing the default JRE may cause a build to occur if you have auto build enabled (Project > Build Automatically or in the General > Workspace preference page).

Java development tools (JDT)

Adding a new JRE definition
Choosing a JRE for launching a project
Working with JREs

Installed JREs preference page