twig-debugging.md

Enabling Twig Debugging on a Drupal 8 site

Confirm your site is utilizing a /sites/default/settings.local.php file. If not, copy and rename /sites/example.settings.local.php to /sites/default/settings.local.php. Note that this file includes the /sites/development.services.yml file by default (around line 39).

Edit your /sites/development.services.yml file and add the following to the "parameters" section:

twig.config: { debug: true, auto_reload: true, cache: true, }

The end result should look like this:

parameters:
  http.response.debug_cacheability_headers: true
  twig.config: { debug: true, auto_reload: true, cache: true, }
services:
  cache.backend.null:
    class: Drupal\Core\Cache\NullBackendFactory

Close and save the /sites/development.services.yml and rebuild caches.