Accessibility Testing in Google Slides

Color Contrast Checker


Color blindness affects 1 in 12 men and 1 in 200 women. Make sure to check the color contrast of the content in the presentation. The WCAG guidelines require a color contrast ratio of 4.5:1. You can use different tools to check the color contrast between the background and foreground. Learn how to use the color contrast checkers on the accessible content page.

Accessibility Checker


Google Slides does not have a built-in accessibility checker. You can use the Grackle Slides add-on to run the accessibility tests on your presentation. Learn how to install Grackle Slides.

Once you have installed Grackle Slides, follow these steps to run the accessibility checker:

  1. Go to Add-ons > Grackle Slides > Launch.
    Launch grackle
  2. Grackle Slides will run the accessibility tests, and a panel appears showing passed and failed tests.
    Grackle accessibility test
  3. You can click on each failed test to view the details of the issue and how to fix it.
    Grackle error example
  4. Go through the list and fix the accessibility issues.

Manual Testing


The accessibility checker does not cover all the accessibility issues. You still need to check the following issues manually:

  • Valid alt text: make sure the alt text conveys the meaning of the content.
  • Valid hyperlinks: make sure the hyperlinks are correct by testing and following the link to be sure the page you are linking to is still valid.
  • Text in images: make sure the images do not include text except for a logo. And if you do not have a choice, add all the text in the image as alt text, or display the text on the screen in the form of a figure caption.
  • Color contrast