Use Hierarchical Headings
Documents should use structured, hierarchical headings to indicate the structure of the document to people using assistive technology. Properly used headings break up text for both sighted and non-sighted users and create content with a consistent look and feel.
Individuals can use the screen reader to scan the content or jump to a particular section of the content using headings without having to read the entire document. Depending on the document type, headings can automatically be used as bookmarks or for a table of contents.
Using accessible headings in a document does not mean simply changing the way text looks — you have to use the tools in the software to apply the appropriate “tags” to the text. Always choose the heading level based on content hierarchy, not based on appearance.
Make Text Size Legible
In most cases, 11 point font is the minimum recommended font size for body text in a document. Some font families designed to be legible at smaller sizes (such as Open Sans) can be appropriate at 10 points for body copy and 9 points for footnotes.
It is also recommended to set line spacing (or leading) to 1.5 times the font size for increased legibility. This means if your body copy is set to 11 points, you should set the line spacing to at least 16 points.
Provide Alternative Text for Images
Images that provide content or serve a function need equivalent alternative text. This text will be read aloud to a person using a screen reader to tell them what is in the image. Images may include photographs, graphs, charts, diagrams and more.
Use Tables To Present Tabular Data
Tables should only be used to present related information in a series of columns and rows — not to control the document’s layout. People using assistive technology rely on correctly structured and configured data tables to be able to perceive and understand the information in a table.
Write Accessible Link Text
Link text in documents should be written in a way that indicates what will happen or where users will go if they click on the link. Additionally, links should be consistently styled to look visually different from the body of the page with underlines or something other than color alone. Best practice is to use at least two visual indicators to indicate a link.
Use Appropriate Contrast
When choosing colors to use in a document, it is important to consider the contrast, especially between text color and its background. Hyperlinks should be distinguishable from the background color and from the color of the surrounding text; if this contrast ratio can’t be met, use an additional visual indicator to indicate a link.
Don’t Use Color Alone To Convey Meaning
Some people can’t distinguish between certain colors or may be using assistive technology to perceive your content. For these cases, it is important not to use color alone to convey meaning. A common example is using red to denote something is an error or otherwise incorrect. Instead of using only color to show this, use words to label the error.
Use Lists Appropriately
Just like headings, lists get labeled in a special way for assistive technology when used appropriately. In documents, this typically means using the list feature instead of manually typing in a character to visually indicate a list.
- Use bulleted lists to list out a group of items that do not have or need a specific order or hierarchy.
- Use numbered lists to present a group of items where the order matters, such as in instructions.
Write for Your Audience
Using plain language ensures that your content is readable and usable for a broad audience. Plain language may look different depending on the audience and context of the content. Take into consideration who will be reading your content and under what circumstances.
Include Navigation Landmarks
Using landmarks like table of contents, page headers, footers, page numbers and page counts can help orient your readers within your document. These landmarks are especially helpful in long documents.
Identify the Document Language
To ensure that screen readers will read a document using the appropriate language profile, the language of the document must be identified.
Most document authoring tools provide a means of identifying the document language as well as the language of specific parts. Leading screen reader software is multilingual, and can read content in English, Spanish, French, and a wide variety of other languages.
You should also identify the language of any content written in a language other than the document’s default language. With this information, supporting screen readers will switch between language profiles on the fly.
Preserve Accessibility When Exporting to PDF
To make an Adobe PDF document accessible, it must be a “tagged” PDF, with an underlying tagged structure that includes the features previously described. Make sure to enable any accessibility tools available in your software to export your document as a tagged PDF.