Typography | Mozilla Protocol

Typefaces

Protocol comes with four fonts: Mozilla Headline, Mozilla Text, Metropolis, and Inter.

Mozilla branded websites use Mozilla Headline for titles and Mozilla Text for body text. We recommend Mozilla Headline only for text over 24px (below should be Mozilla Text).

Firefox branded websites use Metropolis for titles and Inter for body text. Don’t use Metropolis for body text.

Inter

Inter is an open source, sans-serif font designed by Rasmus Andersson. This is our standard type face for body copy in Firefox and is used as fallback font in Mozilla brands. If you need to declare it specifically (such as to override some other inherited font) you can use the mixin @include font-base;.

Download from https://rsms.me/inter/

AaBbCcDdEeFfGgHhIiJjKkLlMmNnOoPpQqRrSsTtUuVvWwXxYyZz AaBbCcDdEeFfGgHhIiJjKkLlMmNnOoPpQqRrSsTtUuVvWwXxYyZz ÅåÂâÀàÁáÄäÃãĄąẢảĆćÇçĈĉĐđÉéÏïÎîŁłÑñØøÖöÕõÜüÛû 123456789 . … , · • : ; ¡ ! ¿ ? { } [ ] ( ) / — – - _ * ‹ › « » ‚ ‘ ’ „ “ ” ' | ¦ @ & † ‡ ❡ ¶ § ◊ ^ ~ © ® ℗ ™ ≈ ~ = ≠ ∙ ÷ ¬ − + ± × ∕ > ≥ ∞ < ≤ % ‰ ∫ ∂ ∆ ∏ ∑ √

Mozilla

Mozilla Headline and Mozilla Text are our custom typefaces for the Mozilla brand. This typeface font family features a unique uniwidth design. It maintains standardized spacing and kerning across all weights and styles, eliminating risk of text reflow to preserve the integrity of the layout and enhance the user’s experience. Read more about Mozilla’s rebrand here

You can declare Mozilla Headline explicitly with the mixin @include font-mozilla-headline;.

You can declare Mozilla Text explicitly with the mixin @include font-mozilla-headline;.

Mozilla Headline

Mozilla Text

Metropolis

Metropolis is a free, open source font used for headlines on marketing and product web experiences. It’s a geometric sans-serif font by Chris Simpson, very similar in style and character to Firefox Sharp Sans, the proprietary font used to create logo lockups for Firefox products (do not use Firefox Sharp Sans as a webfont).

Use Metropolis for large text like headings. As a general rule, type set in Metroplis should stand out. Avoid stacking two sizes of Metropolis one on top of the other. Pair headings in Metropolis with subheadings in Inter.

You can declare Metropolis explicitly with the mixin @include font-firefox;.

Don’t italicize Metropolis. Protocol only includes regular and bold versions of this font.

Download from Fonts Arena

Type Scale

We limit the number of text sizes to a predetermined set, to maintain consistency and avoid sizing text willy nilly in designs.

Title 2XL Title XL Title LG Title MD Title SM Title XS Title 2XS Title 3XS Body XL Body LG Body MD Body SM Body XS

The title sizes are 3XS through 2XL. Of these, the most commonly used are SM, MD, LG, and XL. Use the XS, 2XS, and 3XS title sizes sparingly for labels and UI elements, and the 2XL title size sparingly to make an especially bold statement.

We use three sizes of regular body copy: MD, LG and XL. Use MD for normal, default body text and LG when you need slightly larger text to stand out, like the introduction to an article. The XL body size is useful for taglines or subtitles, but not for long passages of text. There are two sizes of smaller body text: SM and XS, used sparingly for supporting text like footnotes or disclaimers, never for main body copy.

Themes

Protocol includes different branded themes for Mozilla and Firefox, and each theme uses different fonts with a slightly altered scale. Titles set in Mozilla Headline for the Mozilla brand are slightly larger than their Firefox equivalents, adjusting for Mozilla Headline being overall a smaller display font.

Condensed Type Scale

As you can see above, the standard Protocol type scale features big sizes for headings and titles appropriate for most general websites (like marketing sites, blogs, etc). Protocol also includes an alternative, condensed scale with smaller sizes more suitable for web applications.

Title 2XL Title XL Title LG Title MD Title SM Title XS Title 2XS Title 3XS Body XL Body LG Body MD Body SM Body XS

Code

We use Sass mixins to declare these font sizes:

@include text-title-2xl;
@include text-title-xl;
@include text-title-lg;
@include text-title-md;
@include text-title-sm;
@include text-title-xs;
@include text-title-2xs;
@include text-title-3xs;
@include text-body-xl;
@include text-body-lg;
@include text-body-md;
@include text-body-sm;
@include text-body-xs;

Those mixins include media queries to adjust the sizes at key breakpoints. Text gets bigger as the viewport gets bigger. You can resize your window to see this in action on the samples above or on most of our components.

The sizing mixins in turn use another mixin to convert a pixel size to rem for output, assuming a 16px root size (the default in graphical browsers). Because we use rem for font sizing all of our declared sizes are really just suggestions and the end user can resize as they see fit. Text sizes are always variable so design accordingly.

Title utility classes

There are also a set of CSS utility class names available to use directly on HTML heading elements for convenience.

<h1 class="mzp-u-title-2xl">Title 2XL</h1>
<h2 class="mzp-u-title-xl">Title XL</h2>
<h3 class="mzp-u-title-lg">Title LG</h3>
<h4 class="mzp-u-title-md">Title MD</h4>
<h5 class="mzp-u-title-sm">Title SM</h5>
<h6 class="mzp-u-title-xs">Title XS</h6>
<h6 class="mzp-u-title-2xs">Title 2XS</h6>
<h6 class="mzp-u-title-3xs">Title 3XS</h6>