Naming convention

The DNB Design System Eufemia uses the following naming conventions.

Formatting styles

  • pascal case also known as upper camel case. Every word upper case. Example: PascalCase
  • camel case also known as lower camel case. First word lower case. Example: camelCase
  • kebab case also known as kebab case. Only lower case letters. Example: kebab-case
  • snake case. Only lower case letters. Example: snake_case

React components

  • React Components, both as files and as components use pascal case.
  • The folder containing the component uses kebab case.

Web components

  • Web components use kebab case.
  • They are prefixed with: dnb-


  • CSS classes and the files containing the styles use kebab case.
  • CSS classes are prefixed with: dnb-
  • CSS Custom Properties (CSS Variables) use kebab case.
  • SCSS Mixins use camel case.


  • Functions and Variables use camel case.
  • Classes use pascal case.
  • Other JavaScript files use kebab case.

Events and Properties

  • Event names use camel case.
  • They have to describe what they are aiming to do. Like: onClick

NB: Existing components use snake case (on_click) – but you are free to use camel case.


  • Icon names use snake case.
  • They have to describe what they are aiming to meant for. Like: chevron_right
  • Sizes are added as a postfix. Like: chevron_right_medium
  • Only alphabetic characters (a to z) without special chars, due to import statements.
  • Figma icon naming has to match the same (icon archive) as they will define the import names.
  • Figma page and frame names (icon archive) do have to consist the same, due to the automated import mechanism.


  • Pages and directories use kebab case.

Why snake_case property naming

The decision to use snake_case was made to not just adopt React terms (camelCase), because we wanted to be open for future changes in the front end world.

But also the technical limitation that Web Components do not support camelCase made us more confident to use another case style.

HTML attributes uses kebab-case, so we needed something between.

The aspect to distinguish between case styles will also make code easier to read and support future code changes and refactoring.

<Component aria-hidden="true" myReactProp={...} on_click={...} />

Update: Eufemia does not need to support Web Components anymore. That makes it possible to use camel case for React Component Properties.