With text making up so much of the digital content that we consume, keeping it accessible is a crucial step in reducing barriers to information, so typography, typeface, and font selection are all things to take into consideration when planning and producing content. While typography refers to how the text is actually presented on a page or interface, typefaces are the sets of characters used to generate that text—for example, Arial, Times New Roman, and Droid Sans—and each one is made up of a set of fonts. Each of these fonts has a unique combination of characteristics including weight, style, and size. So a bold size 10 Arial would be one font while bold size 20 Arial would be another.
Though the Web Content Accessibility Guidelines (WCAG) don’t define specific accessible fonts, the principle for perceivable content states that “information and user interface components must be presentable to users in ways they can perceive,” which can serve as the foundation for selecting and using fonts with accessibility in mind.
While there are several typefaces and fonts available to choose from these days, using the most widely available options is a good practice. This makes it easier to ensure that users will have access to the content in the way you intend to present it and that the experience will be more consistent across different devices and browsers.
Helvetica and Arial are among the fonts that are considered the most common and safest to use. Others such as Verdana are also becoming more widely used. Since browsers will rely on their own default when a font isn’t available, in the case that an uncommon or completely custom font is being used, defining fallback options is a great way to help create a more consistent experience.
WCAG guideline 1.4 defines how to make content more distinguishable. In relation to text content, this looks at ways of ensuring text is easy to see and that there is a clear separation between the foreground and background.
In most cases, simpler typefaces will be easier to read, and very complex, decorative, or handwritten typefaces are best avoided. As such, sans serif fonts—those without the decorative strokes seen in Times New Roman, for example—are typically considered easier to read, but this isn’t universally true. Sometimes sans serif typefaces may have characters that look very similar, so choosing one with distinctly designed characters will help improve readability.
One challenge that may come up when selecting fonts is the fact that an option that could be easier for some people to perceive may be more difficult for others. For example, the simplicity of a sans serif font may improve the readability of text for a user with a visual impairment while a user with dyslexia may find the characters difficult to tell apart. There are some fonts that have been designed specifically for accessibility, such as Tiresias and OpenDyslexic, but common options such as Arial, Helvetica, Open Sans, and Verdana are also solid choices.
Even when using a typeface that is considered accessible, it’s possible to use it in ways that can create barriers for users. To avoid this, using fewer fonts and using them in a way that users expect is preferred. The minimum expected font size is usually 12 points, but 16 points can improve readability for many. It’s considered best practice to avoid using bolded, italicized or otherwise stylized fonts to convey meaning, and having the right balance of contrast is important. Though pure white backgrounds and pure black text may seem like an obvious choice the contrast can actually be too strong, so opting for off-white and off-black is often a better choice.
WCAG success criterion 1.4.12 provides guidance on how to meet text spacing requirements, stating that the visibility and functionality of content must not be lost if the user sets line height to 1.5 times the font size, paragraph spacing to 2 times the font size, letter spacing to .12 times the font size and word spacing to .16 times the font size.
When it comes to choosing and using fonts, it may be challenging to meet every individual’s needs, but by making mindful decisions, listening to users, and responding to their feedback, creating an experience that is accessible to a large audience is possible.