Customization ============= The look and feel of the Swagger UI can be customized. Overwrite Twig Template ----------------------- If you want to customize parts of the template, you can create your own Twig template. This allows to change the title, the header, add additional or replace existing styles or scripts. Take a look at the Twig documentation `how to extend templates `_. The following example will add additional scripts and a custom style to the template. Just create a file ``templates/bundles/NelmioApiDocBundle/SwaggerUi/index.html.twig``. .. code-block:: twig {# templates/bundles/NelmioApiDocBundle/SwaggerUi/index.html.twig #} {# To avoid a "reached nested level" error an exclamation mark `!` has to be added See https://symfony.com/blog/new-in-symfony-3-4-improved-the-overriding-of-templates #} {% extends '@!NelmioApiDoc/SwaggerUi/index.html.twig' %} {% block stylesheets %} {{ parent() }} {% endblock stylesheets %} {% block javascripts %} {{ parent() }} {% endblock javascripts %} You can have a look at the original template to see which blocks can be overridden.