Acorn

Acorn is the design system for Firefox.

Acorn is the design system for the Firefox desktop, as well as our iOS and Android browsers. It’s a curated library of design, content, and development decisions that built the Firefox you know and love. Acorn is for the global community of employees, contributors, and volunteers that make Firefox better every day.

Mighty oaks from little acorns grow.

Why ‘Acorn’? Besides being a preferred snack of red pandas (also known as firefoxes), an acorn is too heavy to be spread by the wind. Instead, it’s thanks to the tireless toiling of the forest’s smallest creatures that towering canopies of oak trees can grow.

We hope you’ll use this seed to grow Firefox and help the internet blossom into something better.

Explore Acorn

Get started

Start designing and building with Acorn

Foundations

Core building blocks of Firefox experiences

Content

How to write for Firefox

Desktop

Guidelines for creating Firefox desktop experiences

Mobile

Guidelines for creating mobile Firefox experiences

Support

How to work with the Acorn team

More from Firefox and Mozilla

Firefox UX Blog

As we learn and grow our design practice, we write about our findings. Includes posts from Firefox Content Designers, Researchers, and Product Designers.

Firefox Brand Guidelines

These guidelines document the Brand System as it applies to brand design and marketing applications. It includes positioning, voice and tone, and visual elements.

Mozilla Protocol

Mozilla maintains a design system used for marketing websites. If you're designing a Mozilla product, start here.

Mozilla Careers

If you like the work we're doing and want to join us, here is a link to open roles.