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Understanding Accessible Fonts and Typography for Section 508 Compliance

In the realm of digital content creation, people often ask, “What does it mean for an accessible font to be accessible?”

First, neither Web Content Accessibility Guidelines (WCAG) nor Section 508 specifies typefaces nor even a minimum font size. However, government websites need to have clear and consistent headings and highly legible text. The bottom line is typography choices have a huge impact on accessibility.

An accessible font means using a typeface designed for easy reading by a diverse audience, including individuals with visual impairments such as low vision or reading disability such as dyslexia. Accessible typography ensures that textual information is accessible to all users, irrespective of their abilities or disabilities.

What is in Regulation about Typography?

Before delving into recommendations from experts found on the internet, let’s explore the Section 508 Standards and other regulations that help authors choose their text.

Americans with Disabilities Act (ADA) and Architectural Barriers Act (ABA)

The ADA and ABA accessibility standards require sans-serif fonts in a few places.

Section 508 Standards

  • 402.4 Characters on Display Screens [for ICT with closed functionality]: At least one mode of characters displayed on the screen shall be in a sans serif font. Where ICT does not provide a screen enlargement feature, characters shall be 3/16 inch (4.8 mm) high minimum based on the uppercase letter “I”. Characters shall contrast with their background with either light characters on a dark background or dark characters on a light background.

Why Sans Serif?

Most print publications use a serif font, one with the small flourishes at the tip of letters such as Times New Roman. With serif fonts being the norm in print, it might seem odd accessibility regulations require sans serif but there is good reason. For people with good vision, a typeface with serifs is slightly easier and faster to read than one without serifs. Typically, for people with low vision, the serifs significantly degrade legibility. The importance of using a sans serif typeface is especially important for digital content since it is typically read on-screen and not in hardcopy print.

It’s okay to use serif fonts for headings or other emphasis. Sans serif is most important for body text and fluid reading.

Why 3/16 inch?

Accessibility regulations specify a measurement of 3/16-inch-high minimum based on the uppercase letter “I,” which is not a metric traditionally associated with typography. This is because the regulation must work “in the field” for third-party testing. For most typefaces, this works out to 16 pt.

Should electronic documents use 16 pt for body text?

Please no! That is a minimum size when a reader cannot adjust the size. For websites and documents, the user has control over “zoom” so use a typical font size of 11 or 12 pt.

Is it okay to use small fonts in electronic documents?

People with low vision typically use magnification settings optimized for the standard body text of 11 or 12 pt. The net effect is like having a very small screen; “looking through a soda straw” is a common analogy. Smaller fonts require the user to “zoom in” more, which breaks the reading flow. Typical use of subscripts and superscripts is not problematic, but running text at less than 9 pt, such as in a long footnote, is creating a barrier. For a similar reason, very large fonts, such a heading, should be avoided. Very large text forces a reader with low vision to “zoom out” and reorient to their place on the page.

More Important Than Typeface

While the author’s choice of a font is important, and the focus of this article, it is important to note there are factors that have a more significant impact on readability and accessibility. The WCAG success criteria address these issues.

1.4.1 Use of Color: Color must not be the only means of conveying information. If color signifies meaning, incorporate additional visual cues like a symbol or text to convey the information.

1.4.3 Contrast: Text and images of text must have a contrast ratio of at least 4.5:1. Large text, such as 16 pt bold, and icons need a 3:1 ratio between foreground and background colors. This contrast requirement applies to text over a gradient or background image. An author might put a dark rectangle behind light text, or use black text with a thin white outline effect.

1.4.4. Resize Text: The reader must be able to resize text to at least to 200 percent without loss of content or functionality. Web browsers and word processors include this feature by default, but document authors can interfere with this functionality.

1.4.5 Images of Text: Whenever possible, use actual text and not images or pictures of text. This gives the reader control over the presentation of text. Images of text also degrade and become jagged when high levels of screen magnification are used.

1.4.10 Reflow (WCAG 2.1 AA): Readers using assistive technology for magnification are essentially using a window half the typical size. Content should reflow and not require horizontal scrolling when read using a small, resized window.

1.4.12 Text Spacing (WCAG 2.1 AA): Content should not be lost if a reader uses assistive technology to make minor adjustments to paragraph, line, word, or letter spacing.

U.S. Web Design System (USWDS)

Federal websites are required by the 21st Century Integrated Digital Experience Act (21st Century IDEA) to utilize the U.S. Web Design System (USWDS). This design system offers guidance, components, design tokens, and utilities for content creators, covering typography and typesetting for enhanced accessibility. The import role of the USWDS was reinforced OMB M-23-22.

Additional Reading

Typography is a wide and deep topic. For more information about accessible fonts and typography, we share these .gov resources:

In conclusion

Accessible fonts and typography are indispensable components of Section 508 compliance and digital inclusivity. By considering the guidelines and recommendations outlined here, content creators can ensure their digital content is accessible to all, fostering a more inclusive and equitable online environment.

Reviewed/Updated: September 2023

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