People with a variety of print disabilities (including low vision, dyslexia, other cognitive disabilities) can benefit from being able to increase the spacing between lines, words, and/or letters on their own device.
Color-contrast-checking tools can compare two colors and report on the contrast ratio between them. Some tools will allow you to adjust these values until the ratio is sufficient, helping you to choose a color scheme that avoids contrast problems.
Adding structure to web content makes it more readable and comprehensible to everyone and especially to people with a visual or cognitive impairment that makes reading on-screen content difficult.
Headings are used to group and label sections of content, giving visual structure to the page and providing a means of navigation to screen reader users.
Readable content is accessible content. You should aim to choose words and sentence structures that are not difficult or unnecessarily time-consuming to read for your target audience.
Avoid referring to a button, menu, or other item in the page only by its position on the page; instead, use additional information that describes the content.
When you include a list in your page content, this relationship needs to be conveyed visually, and it also needs to be conveyed to people using screen readers.
Headings are important orientation aids, and they help people quickly identify the content on your page. When headings are correctly identified, they also allow screen reader users to quickly navigate from heading to heading.
Paragraphs of text are a fundamental core of web content. It's important to display them in a fashion that is optimally readable to the majority of your audience.