Debugging in the Just-In-Time Mode
IntelliJ IDEA supports the use of Xdebug in the Just-In-Time (JIT) mode so it is not attached to your code all the time
but connects to IntelliJ IDEA only when an error occurs or an exception is thrown. The Xdebug operation mode is toggled
through the xdebug.remote_mode setting, which is by default set to
The mode is available both for debugging command-line scripts and for web server debugging.
On this page:
- Configuring Xdebug for using in the Just-In-Time mode
- Debugging session
Configuring Xdebug for using in the Just-In-Time mode
Depending on whether you are going to debug command-line scripts or use a Web server, use one of the scenarios below.
Command-line scriptsFor debugging command-line scripts, specify the custom
-dxdebug.remote_mode=jitdirective as an additional configuration option:
- Open the Settings / Preferences Dialog by pressing Ctrl+Alt+S or by choosing for Windows and Linux or for OS X, and click PHP under Languages&Frameworks.
- From the PHP executable drop-down list, choose the relevant PHP interpreter and click next to it.
- In the Interpreters dialog box that opens, click next to the Configuration options text box in the Additional area.
In the Configuration options dialog that opens, click to add a new entry, then type
-dxdebug.remote_modein the Configuration directive field and
jitin the Value field.
Web server debugging
- On the main menu, choose .
In the Web Server Debug Validation Dialog that opens, choose the Web server to validate the debugger on.
Choose Local Web Server or Shared Folder
to check a debugger associated with a local Web server.
- Path to Create Validation Script: In this field, specify the absolute path to the folder under the server document root where the validation script will be created. For Web servers of the type Inplace, the folder is under the project root.
URL to Validation Script:
In this text box, type the URL address of the folder where the validation script will be created.
If the project root is mapped to a folder accessible through
http, you can specify the project root or any other folder under it.
Choose Remote Web Server
to check a debugger associated with a remote server.
- Path to Create Validation Script: In this field, specify the absolute path to the folder under the server document root where the validation script will be created. The folder must be accessible through http.
In this field, specify the server access configuration of the type Local Server
or Remote Server to access the target environment.
For details see Configuring Synchronization with a Web Server.
Choose a configuration from the drop-down list or click the Browse button in the Deployment dialog.
- Choose Local Web Server or Shared Folder to check a debugger associated with a local Web server.
- Click Validate to have IntelliJ IDEA create a validation script, deploy it to the target remote environment, and run it there.
php.inifile which is reported as loaded and associated with Xdebug.
php.inifile, find the
[XDebug]section and change the value of the
xdebug.remote_modefrom the default
Set the breakpoints and launch a debugging session, as described in Initiating a Debugging Session or Debugging with a PHP Web Application Debug Configuration.
Xdebug connects to IntelliJ IDEA in the following two cases:
- When an error occurs. In this case, Xdebug stops on the line right after the error condition. The reason for that is that IntelliJ IDEA first has to run the erroneous code before it knows something is wrong.
When an exception is thrown. If the exception is handled, Xdebug breaks at the first line of the
catchblock if there is one, or at the