Theming in Drupal 10: What’s Changed and What You Need to Know

Drupal 10 brings notable improvements to the theming experience, making it more modern, maintainable, and user-friendly for frontend developers. If you’ve worked with previous versions of Drupal, the changes in Drupal 10 will feel like a breath of fresh air.

Let’s break down what’s new and how you can take advantage of it.

Goodbye to PHPTemplate, Hello to Twig

Drupal 10 continues the move away from PHPTemplate by fully embracing Twig as its default templating engine. Twig is cleaner, more secure, and easier to learn. It also encourages separation of logic and markup—making your themes easier to maintain.

New Starterkit Theme Generator

The new Starterkit theme approach replaces sub-theming from core themes like Classy or Stable. With Starterkit, you now copy core theme files to create your custom theme, rather than inheriting them. This provides a safer, more stable path to theme customization without breaking updates when core themes change.

Olivero: A Beautiful Default Theme

Drupal 10 ships with Olivero, a modern, accessible, and mobile-first front-end theme. It’s a massive leap forward from Bartik and designed to support the latest features, like Layout Builder and media embedding.

Claro: Better Admin Theming

The Claro admin theme provides a modern, clean UI for content editors and site managers. It’s accessible, responsive, and replaces the outdated Seven theme.

Symfony and Theme Libraries

With the Symfony 6 upgrade in Drupal 10, the theming layer now plays more nicely with modern frontend workflows. You can more easily integrate JS and CSS libraries using libraries.yml, and the structure feels more intuitive.

What This Means for Site Builders

• You don’t need to unlearn everything—but you should stop relying on sub-theming Stable.

• Invest time in learning Twig if you haven’t already.

• Start with the Starterkit theme when beginning a new project.

• Take advantage of Claro and Olivero—they’re not just pretty; they’re powerful.

Need Help With Drupal 10 Theming?

Upgrading your theme or starting from scratch in Drupal 10? Our frontend experts at Drupalify can help bring your brand to life with a responsive, maintainable, and future-proof design.

You can also book a consultation to talk through your theming goals with a tech lead.

FAQs

Do I need to rebuild my existing theme for Drupal 10?
Not necessarily, but if it’s based on an old sub-theme (like Stable), moving to a Starterkit-based theme is recommended.

Can I still use Classy or Stable in Drupal 10?
They’re deprecated. You can still use them, but they won’t receive updates and could cause issues long-term.

Is Twig easy to learn for someone used to PHPTemplate?
Yes! Twig uses a simpler, cleaner syntax and is widely documented.

Will Claro become the default admin theme?
It already is in Drupal 10, offering a better UX for content editors and admins.