Run/debug configurations
IntelliJ IDEA uses run/debug configurations to run, debug, and test applications. A run/debug configuration represents a set of startup properties, such as VM options or JRE, that are used to run the program.
There are two types of run/debug configurations:
Temporary – created for you when you are running a class that does not have a permanent configuration. It provides the bare minimum that allows a class with the
main()method to run. Temporary configurations are deleted when their number exceeds the maximum.Permanent – created explicitly from a template or by saving a temporary configuration. Permanent configurations remain as part of your project until you remove them.
Permanent configurations have opaque icons while the icons of temporary configurations are semi-transparent.
Whenever you perform run, debug, or test operations, IntelliJ IDEA either uses an existing run/debug configuration or creates a new temporary one.
Change the maximum number of temporary run/debug configurations
By default, only 5 temporary run/debug configurations are allowed per project. When the limit is exceeded, the oldest temporary run/debug configuration is replaced by the new one. To change the limit:
From the main menu, select . Alternatively, press Alt+Shift+F10 then 0.
From the list, select Templates, then in the right-hand pane, configure the Temporary configurations limit parameter.
Create permanent run/debug configurations
IntelliJ IDEA provides the following ways to create a permanent run/debug configuration:
When there is an executable class or method, you can create a permanent run/debug configuration right from the editor.
Create from a template or copy an existing configuration.
Create a permanent run/debug configuration from a test method or class
Place the caret at the declaration of an executable method or class (for example a class with the
main()method or a test suite) and press Alt+Enter. IntelliJ IDEA creates a permanent run/debug configuration of the corresponding type.
Set up the run/debug configuration parameters. For the detailed description of the template, see the respective section of run/debug configurations reference.
Save a temporary configuration as permanent
Select the temporary configuration in the run/debug configuration switcher and then click Save Configuration.
Create a run/debug configuration from a template
From the main menu, select . Alternatively, press Alt+Shift+F10 then 0.
In the Run/Debug Configuration dialog, click
on the toolbar or press Alt+Insert. The list shows the run/debug configuration templates. Select the desired template. If you are not sure which template to choose, refer to Run/debug configurations dialog for more information on particular templates.
Specify the run/debug configuration name in the Name field. This name will be shown in the list of the available run/debug configurations.
Select Allow parallel run if you want to allow multiple instances of this program to run at the same time. If this option is disabled, attempting to re-run the application will terminate the active session.
Set the run/debug configuration parameters. The list of mandatory and optional parameters may vary depending on the selected run/debug configuration type.
For the detailed description of the selected template, see the respective section of run/debug configurations reference.
In the Before launch section, define whether you want to perform any specific actions before launching the application, for example, compile the modified sources or run an Ant or Maven script.
For information on particular Before launch activities, refer to Before Launch
Apply the changes and close the dialog.
Share run/debug configurations
If you are working in a team, you might want to share your run/debug configurations so that your teammates could run the application using the same configuration or enable them to remotely attach to the process you are running.
For these purposes, IntelliJ IDEA provides a mechanism to store your run/debug configurations as project files and share them through VCS. The same mechanism can also be used when you want to send your configuration as a file to someone else. This saves a lot of time as run/debug configurations sometimes get sophisticated, and keeping them in sync manually would be tedious and error-prone.
Go to the properties of the run/debug configuration you want to share (), enable the Store as project file option, and specify the location where the file will be stored.
If compatibility with IntelliJ IDEA 2019.3 and earlier is required, store the file in the default location.
To learn how to use version control systems in IntelliJ IDEA, refer to the Version control topic.
Run/debug configuration templates
For a run/debug configuration of a particular type, you can set up the default values for one or more parameters and save them as a template. In this case, the next time when you create a new configuration of that type, the corresponding fields of the dialog will already contain the specified values.
Configure the default values for a template
From the main menu, select . Alternatively, press Alt+Shift+F10 then 0.
In the left-hand pane of the run/debug configuration dialog, expand the Templates node and select the desired configuration type. The corresponding configuration template appears in the right-hand pane.
Specify the desired parameters and click Apply to save the template.
Compound run/debug configurations
Suppose you would like to launch multiple run/debug configurations simultaneously. For example, you may want to run a sequence of test configurations, or run configurations for JavaScript and HTML files in one go. You can configure this behavior with a compound run/debug configuration.
When you run or debug your code using a compound configuration, you actually launch a sequence of configurations in the order they are listed.
Create a compound run/debug configuration
From the main menu, select . Alternatively, press Alt+Shift+F10 then 0.
In the Run/Debug Configurations dialog, click
or press Alt+Insert, then select Compound. Specify the run/debug configuration name in the Name field. This name will be shown in the list of the available run/debug configurations.
To include a new run/debug configuration into the compound configuration , click Add
and select the desired one from the list. Apply the changes.
Run/debug configuration folders
When there are many run/debug configurations of the same type, you can group them in folders so they become easier to distinguish visually.
Once grouped, the run/debug configurations appear in the list under the corresponding folders.
Create a folder for run/debug configurations
From the main menu, select . Alternatively, press Alt+Shift+F10 then 0.
In the Run/Debug Configurations, select a configuration type and click
on the toolbar. A new empty folder for the selected type is created. 
Specify the folder name in the text field to the right or accept the default name.
Select the desired run/debug configurations and move them under the target folder.
Apply the changes. If a folder is empty, it will not be saved.
When you no longer need a folder, you can delete it Delete. The run/debug configurations grouped under this folder will be moved under the root of the corresponding run/debug configuration type.