Typography refresh

Summary of changes
We approached this update to Wikimedia's default typography with the following requirements in mind:


 * 1) Readability: Typefaces must be legible and beautiful at all sizes. Type as an element must help differentiate the interface (such as site navigation) from article content.
 * 2) Consistency: A consistent visual experience across desktop and mobile devices.
 * 3) Availability: All typefaces we use must be already usable (or made available) on all platforms where Wikimedia projects are present. Any selections must degrade gracefully across devices and platforms (Mac OS X, Windows, Linux, and mobile operating systems).
 * 4) Accessibility: Wikimedia content must be highly accessible to all, including those with impairments.

In that context, we've made the following changes:


 * New font specifications: We have set the following font families: heading styles have been set to "Linux Libertine, Georgia, Times, serif". Body copy (the main text of pages) has been set to "Arimo, Liberation Sans, Helvetica Neue, Helvetica, Arial, sans-serif".


 * Note that these lists do not mean you will receive all of these fonts. Rather, your browser and operating system will look for the first font in the list that you have downloaded, and will present that.


 * New spacing and sizing for headings, body copy, and leading: With the current text width, headings need to clearly stand out and the leading (whitespace between lines) needs to be sufficient to enable readability without creating eye fatigue. Headings will now be set to the following: H1 (page titles) will be 2em/1.8em, H2 (main section headings) will be 1.6/1.4em. H3 will be 1.4/1.2em, H4 1.2/1em, H5 1/1em. The body copy has been increased to 0.875em (from 0.8em) with 1.6em (from 1.5em) leading to create more airiness. Depending on your browser and operating system, this will translate to slightly different pixel values, but overall results in a slightly larger body font size.


 * New body font color: In hex triplets, the body copy color is now set to  on , from   on  . In less technical terms, this means the color has changed from pure black text on a pure white background, to very dark grey text on pure white background. (Colors for links, headings, and other elements have not changed.)

FAQ
The following are answers to some key questions about this change.

What was the problem with our typography to begin with?
Text is our core visual element of Wikimedia projects, whether it's an encyclopedia (like Wikipedia) or a smaller project like Wikisource and Wikibooks. We want our users to sense accuracy, reliability, and clarity from our design, just like the actual content they are reading. Prior to this typography update, we had more than 20 arbitrarily defined type sizes on desktop alone, which appeared inconsistent for our users. The type size was too small for many readers, and the line height could make reading long form content difficult. For headings, these should act as entry points in a long pages of text and were styled accordingly to aid readability. We sought to achieve better balance and cohesiveness for users to efficiently scan the page or engage in long form reading.

The functional problems with our older styles were first addressed via improvements to our mobile typography. That gave us a chance to test a larger type size, increased leading, and serif headings. Now, it is time to address readability and accessibility in all languages/projects, as well as create consistency in the design language across desktop, mobile web, and apps.

Is there a perfect font that meets our readability needs in all scripts? Do we think this is it?
No, there is no one perfect font which embodies...
 * 1) Ubiquity: i.e availability on all popular desktop and mobile operating systems.
 * 2) Proper rendering of glyphs and diacritics: for hundreds of non-Latin scripts, as well as good kerning for character pairs, so users do not have to squint to read characters.
 * 3) Respectable x-height: so type is legible at small sizes for things like left navigation, captions, terms of service or secondary information.
 * 4) Hinting: avoiding blurriness of characters at small sizes, particularly on Windows.

We have to make a practical decision based on what comes close to meeting all these requirements, within our constraints. Millions of users read Wikipedia on different devices every day. The current font selections will bring improved readability and consistency across platforms, even if they're not perfect.

Why is the type size and leading increased?
The body copy size is set to 0.875em (14 px) from 0.8em (12.8px).

This is a small, conservative change. The previous type size was unreadable to many users. We found through user feedback that text zooming was used extensively to make the text more readable for those with even basic vision issues or impairments, since we endeavour to make the information accessible to all users, this change felt like a basic requirement for any improvement in this area. Along with the type size the leading has also been increased to 21px leading, following typographic standards for leading i.e 120% of the type size. This helps readers who go past the introduction and read long paragraphs.

Why are we using serif fonts for the headings?
For better contrast and distinction between body and headings. Headings act as entry points when users are scanning a page. Headings add some visual diversity to our font stack. Both headings and images play the important role of breaking up the monotony of the page. Combining serif and sans-serif is not an unusual or original idea.

Why did we specify Linux Libertine, Georgia, and Times as the serif fonts?
Georgia is optimized for browsers and screens. It is also widely available on our most popular platforms, including for users of Windows, Mac OSX, and iOS. Section titles are entry points into the article. A serif font provides some visual differentiation & character from the body copy which helps a user scan the page. Linux Libertine and Georgia acts as good complementary fonts, and pair well with Helvetica and Arial.

Why did we specify new sans-serif fonts?
Of all the free/open options, Liberation Sans and Arimo had the best display characteristics (strong x-height and works well for readability at all sizes). The letterforms closely resemble Helvetica and Arial so it provides for a consistent experience. Arimo had the best technical compliance (accurate rendering of obscure Unicode features), but is only installed by default in ChromeOS. Liberation Sans has a respectable amount of ubiquity and it is produced by Red Hat who can help us with addressing rendering issues.

Why did we include non-free fonts in the font stack?
The stack specified a range of fonts from Helvetica Neue to Arial that are available across all major platforms. Even though Arial is widely used as a default, we need to specify it so there the CSS degradation is predictable. To ensure a reliable experience to users across platforms as best as we can, we decided to include non-free fonts in the stack since many operating systems (such as Windows, MacOS, and iOS) do not have any FOSS fonts installed by default.

It is particularly important to note that, because of the way CSS font-family settings work, specifying a particular font does not create a hard dependency on that font, nor does it cause the user to download that font. This means that fonts we specify only appear if the user has them already, and Wikimedia text will continue to appear regardless of whether you have a particular font or not.

What about using webfonts?
Webfonts is a system to deliver a font to users who do not have it installed. This involves having a user's browser download a font we provide, which causes additional resources to load and would have a negative impact on site performance (i.e. how fast pages load). This is particularly true for older browsers. In the future we may explore using webfonts, but for now this update provides greater readability and consistency while not degrading page load times.

Why did we change the body text color?
The new values (#252525 on #FFFFFF) have a contrast ratio of 15.3:1, which is a AAA rating according to WCAG 2.0 1.4.6. Pure black for both body copy and captions is not recommended against white for several reasons. Dyslexic users are sensitive to the juxtaposition of pure black text on a pure white background due to its high contrast. This can cause the words to swirl or blur together. To avoid this, use a slightly off-white color for your background, like a light gray, or decrease the contrast between foreground (text) and background. For users without accessibility issues, the harsh contrast of pure black on pure white can increase eye strain as well.

How did this change happen?
This typography update was first tested for four months, and then released on mobile web for all Wikimedia projects in October 2012. These included font stack declarations for serif headings and sans serif body copy, as well as increased type size and leading for body copy and captions.

These changes were later brought into desktop as a beta feature, starting in November 2013. This beta feature then went through three major iterations based on community feedback.

How did we get feedback?
Many of the typography changes were first tested on mobile in October 2012, much of the learning was integrated into the typography beta feature for desktop which was launched October 2013 and went through three major releases. During the time the beta feaure was used by over 14,000 users across the top 10 Wikipedias.

Can I opt out of changes to the default fonts?
Yes. It is possible for logged-in users of Wikimedia sites to customize their personal CSS to override the font selection. You can also define the default font your browser uses to display “serif” and “san-serif” fonts, if your system does not have any of these specified fonts this browser preference will be used instead.

Did we test this on a variety of browsers and operating systems?
Yes. The new font stack was tested on the following operating systems: Windows XP, Windows 7, and Windows 8, Ubuntu Linux, Mac OSX 10.8, iOS 6 and 7, Android, and Chrome OS. Size, leading, glyphs, hinting and font renders were tested on Windows, Ubuntu Linux, Mac OS 10.8, Android, and Chrome OS.

How will non-English language projects adapt to these changes?
By default, the typography update will be applied to all projects (as part of the Vector skin). There may be languages that need to override some of these styles to accommodate particular scripts. For example, some scripts may need a taller line height or larger font size. Each wiki can override these particular styles by editing their MediaWiki:Vector.css page. We encourage other projects to audit the changes introduced by the update, and override the CSS only where necessary based on their script.

Also see the issues that we are already aware of regarding other language projects.

What about non-Latin scripts?
The old type size in non-Latin scripts was 0.8em (12.8 px). This squashes glyphs and superscripts significantly along with the type being too small to read. Scripts examined were Urdu, Marathi, Bahasa Melayu, Chinese, Korean, Navajo. The body copy type size increase will improve readability for most scripts. Specifically for Navajo, an override will be provided because character pairs render strangely in Helvetica.

Inline CSS guidance can be provided to ensure that languages make overrides on a case-by-case basis as needed. Please comment on the Talk page if you primarily use a non-Latin script and encounter significant problems.