The Zend Studio debugging function allows you to test your files and applications and detect errors in your code. The debugger allows you to control the execution of your program using a variety of options including setting breakpoints, stepping through your code, and inspecting your variables and parameters.

PHP CLI Application

Allows you to debug files on your workspace using internal debuggers - Zend Debugger, and Xdebug (requires additional installation and configuration).
Internal debuggers enable developers to locally validate freshly developed code before deploying to a Web server. The internal option means that files located on your workspace can be debugged. When debugging internal files the Zend Studio Internal Debugger uses its own PHP executable that was installed together with Zend Studio.

See Locally Debugging a PHP Script for more information.

PHP Web Application

Allows you to debug applications situated on a server. It allows you to debug whole applications, including any required interactive user input.

The PHP Web Page Debug has an option to give the files you are working on first priority when debugging, using the "Local Copy" option. This means that, when possible, file content is taken from the files situated on your Workspace. This prevents you from having to upload the latest revisions.


It's recommended that your local project structure reflect the project structure on your server.

See Debugging a PHP Web Page  for more information.


Your server must be running the Zend Debugger or Xdebug in order for remote debugging and profiling capabilities to function.
The Zend Debugger comes bundled with Zend Studio and Zend Server. For instructions on installing and configuring Xdebug, see Installing Xdebug and Configuring Xdebug.

URL Debugging

Allows you to enter a URL to debug an application on a server. Only server files will be debugged, so the files do not need to exist locally in your Workspace.

See Debugging a URL for more information.


Your server must be running the Zend Debugger in order for remote debugging and profiling capabilities to function.

Toolbar Debugging

Allows you to Debug files and applications directly from your browser using the Zend Debugger Toolbar, available for download from the Zend Studio Resources site (

See Debugging Using the Zend Debugger Toolbar for more information.

Debug Mode

Allows you to listen in on URL requests to a specific Zend Server target, without initializing a debug session from a browser using the Zend Debugger Toolbar or from within Zend Studio. When Debug Mode is enabled for a Zend Server target, all requests matching URL filters associated with a particular target trigger a debug session in Zend Studio. Debug Mode is especially useful when your circumstances do not allow you to set debug parameters in a request, for example, when using a mobile device.

See Using Debug Mode for more information.


It is recommended to use Debug Mode for development purposes. Using this feature in a production environment, will trigger a significantly large amount of debugging sessions in your workspace.