Introduction

Installing Devel

To install Devel using Composer:

$ composer require drupal/devel --dev

Kint should be installed as a dependency for this module if you plan to use it for variable debugging.

If your project doesn't already have Kint installed, you can use composer to install it:

$ composer require kint-php/kint --dev

After installing Kint, the "Kint" radio button should be available under "Variables Dumper" on the "Devel Settings" page.

If the radio button is not visible, try clearing the caches and refreshing the page.

Devel modules

After installing Devel, new Devel modules will be available in the Extend page (/admin/modules):

* As of version: 8.x-3.x, the Devel Kint module is no longer included and should be added separately as a dependency. See "Installing Devel" above for more information.

** As of version: 4.x, the Web Profiler module is not included and is available as a separate module.

Each of these Devel tools can help you with development.

Devel, as the main module must be enabled for the other modules to operate.

Devel functionality

New PHP functions to help with development and debugging. Learn more about dpm() and other Devel functions.

New blocks for quickly accessing Devel pages or masquerading as other users.

Redirecting outbound email to files using a mail-system class.

Container services info page (/devel/container/service) for inspecting Services and Parameters registered in the Service Container.

Routes info page (/devel/routes) for inspecting routes information, gathering all routing data from .routing.yml files and from classes which subscribe to the route build/alter events.

Events info page (/devel/events) for inspecting the event listeners registered in the event dispatcher.

Devel Generate functionality

Preview your theme populated with articles, with comments and users. 

Test permissions and workflow with different user roles.

Demo a site to a client.

Devel Kint

Provides a dpr() function, which pretty prints variables.