This content was taken from this Google Docs Help page: https://support.google.com/docs/answer/6199477?hl=en
Make your document or presentation accessible
When you create a document or presentation, follow the tips below to make sure it's readable by everyone, including people with disabilities.
Include alt text
Include alternative text for images, drawings, and other graphics. Otherwise, screen reader users just hear "image." Some images automatically include alt text, so it's a good idea to verify that this automatic alt text is what you want.
Add or edit alt text
- Select the image.
- Go to Format, then Alt text.
- Enter alt text in the description field.
Use tables for data
Use tables for presenting data, not for changing the visual layout of the page. In the table, include a heading row (rather than starting with data in the first row) because screen readers automatically read the first row as a heading row.
Use comments and suggestions
Use the commenting and suggesting features instead of writing notes within the text of your document or presentation. Screen reader users can jump to comments using keyboard shortcuts rather than hunting through your file. The file owner can also receive email notifications or review comment threads.
Check for high color contrast
High color contrast makes text and images easier to read and comprehend. Web Content Accessibility Guidelines (WCAG) 2.0 recommend a minimum ratio of 4.5:1 for large text and 7:1 for other text and images. For example, avoid light gray text on a white background.
To check contrast, use the WebAIM contrast checker.
Use informative link text
Screen readers can scan for links, so informative link text is helpful. It's best to use the title of the page as the linked text. For example, if you're linking to your profile page, the link text should say "my profile," not "click here" or the full URL.
Check text size and alignment
To make your document or presentation easy to read, use large, left-aligned text when possible. Justified text is more difficult to read because of extra space between the words. To change the alignment, press Ctrl + Shift + L (Windows or Chrome OS) or ⌘ + Shift + L (Mac).
Use text to support formatting
It's best not to rely on visual formatting alone to communicate meaning. Screen readers might not announce formatting changes, such as boldface or highlighting.
For example, to mark an important section of text, add the word "Important."
Use numbered and bulleted lists
Google Docs and Google Slides automatically detect and format some lists for accessibility. For example, if you start a new line in your document by typing the number 1 followed by a period, the new line automatically becomes the first item in a numbered list. Learn how to format bulleted and numbered lists.
Use headings to organize your document
Headings divide your document into sections, making it easier for people to jump to a section (especially if they're using keyboard shortcuts). You can use the default heading styles or create your own. Learn how to add and customize headings.
Include navigation landmarks in your document
Landmarks like headers, footers, page numbers, and page counts help your readers find where they are in your document. To maximize accessibility, especially in long documents, include one or more of these landmarks (available in the Insert menu).
Share a presentation in HTML view
Google Slides HTML view displays your whole presentation in a single, scrollable HTML page, instead of displaying the presentation one slide at a time. This is a helpful feature if your audience includes people who use screen readers.
To access a presentation in HTML view, go to View and select HTML View. You can also use the keyboard shortcut Ctrl + Alt + Shift + p (Windows or Chrome OS) or ⌘ + Option + Shift + p (Mac).