The goal of any presentation is to communicate with your audience, but it's easy to exclude people unintentionally. Below you find some tips how you can make your presentation accessible to everyone in your audience.

Prepare with care.

Create clear, simple slides.

• Please prepare your presentation in the aspect ratio of 16:9 as this is the size of the projectors at the conference.
• Avoid using too many graphics, too much text, or too many animations on the same slide. Visual complexity makes it harder for people to absorb information during your presentation, especially people with a visual or cognitive impairment.
• If your slides use animation, make sure that you don't leave people behind by making important content disappear. If people read more slowly or rely on an interpreter, they might need a bit more time to absorb the content. Avoid using repetitive animation (flashing or flickering), since it can be distracting and can trigger seizures.
• If you'll be using acronyms or technical or obscure terminology in your presentation, include a glossary with definitions. This information is especially helpful for sign language interpreters and captioners.

A note about using slides: If you generally don't use slides when giving a talk, consider giving it a try -- even if you create just one slide with your main points. If you rely only on your voice (that is, you don't provide any visual accompaniment), some people might have difficulty understanding, whether because of a language barrier, cognitive impairment, or being hard of hearing.

Use images carefully, and always use text for critical information.

• Include alternative text (alt text) for any images, drawings, or diagrams to make the graphics accessible to people who rely on screen readers. To add alt text in Google Slides, select the object, then go to the Format menu > Alt text to add or edit the text description.
• If you use an image of text instead of actual text, make sure to include alt text and to use a high contrast ratio. More about contrast ratio is below.
• Charts can be difficult to decipher, especially if they use a small font in order to fit more data. If your slide includes data-heavy charts or graphs, be sure to specify the takeaway either on the slide itself or in the speaker notes.
• Never rely only on color or other visual formatting to convey critical information on a chart or slide. Relying too heavily on visual formatting excludes anyone who is color blind or unable to see the screen. For example, to highlight a new section of a flow chart, don't simply use a different color. Along with the color change, add a textual cue, such as the word "new."

Include captions for video content, and consider real-time captions.

• Provide captions for all audio or video recordings shared in your presentation. If you're using a YouTube video, check that the YouTube automatic captioning is accurate. If it's not, create your own captions in YouTube.
• Consider using real-time captioning for your presentation. As of October Google slides offers that feature for free. More info how to use it can be found here.

For contrast and text size, more is better.

• The difference between text and its background color (or between different parts of an image) is called contrast ratio. A high contrast ratio makes it easier for people to read text or decipher images, especially if they're sitting far away or have low vision or color blindness. For example, pie charts often have different colors for each portion of the pie. For some of those colors, plain black or white text doesn't offer enough contrast. At a minimum, use a 3:1 contrast ratio for large text and 4.5:1 for other text and images. An ideal contrast ratio is 7:1. To check contrast, use the WebAIM contrast checker.
• Recommendations for text size vary. 32 or 40 point text is generally large enough, depending on the size of the room and the screen. Before your presentation begins, go to the back of the room and make sure you can read your slides.

When it's time to present, be present.

Prepare with care.

• Get to your presentation location early and check it out with your audience in mind.
  • Check your audio/visual connectivity and be sure that you have necessary adapters.
  • What's the noise level? Make sure you're prepared to speak loudly or use a microphone if there's ambient noise.
  • Is the room easy to navigate? Remove any obstacles that might get in the way for people who are visually impaired or who use a wheelchair.
  • Is the screen easy to see? Consider reserving space in the front of the room for wheelchairs (if audience members are likely to stand) or for other audience members who might need to be close to the front.
• If you plan to lead an interactive activity, make sure it can include everyone. This applies both to the activity itself and the explanation of the activity.

If it's important, say it out loud.

• Don't let your slides "speak for themselves." If you show a famous quote, read it out loud. If you're using a funny or powerful image, describe it briefly out loud. If you're showing a chart or diagram, explain what it means. Relying too heavily on the audience's ability to see the screen leaves people behind; sometimes people can't see from the back of the room, sometimes the projector is faulty, sometimes a tall person blocks people's view, and sometimes people have no sight. Consider mentioning the slide number for people who can’t see the screen but are following along in their copy of the slides.
• If you show a video that relies heavily on visual information, describe the video out loud before playing it. You might also consider adding an audio description within the video. For an example of audio descriptions, compare these two trailers for Frozen: Official trailer and trailer with audio description. Learn more about adding audio descriptions (DigitalGov article).

Take your time.

• As you move through your presentation, do your best to speak at a slow, conversational pace. Pausing and speaking slowly can be difficult, especially if you're nervous, but it makes it easier for everyone to keep up.
• If you're working with a sign language interpreter, pause at the beginning of each slide so that deaf audience members can look at the slide before you start talking. Pause again if you want to draw attention to the slides, so that the interpreter can wrap up your last sentence and let the audience focus return to the slides. If you ask for audience interaction, look at the interpreter to make sure he or she finished signing your question before you take responses.
• If you use acronyms or technical or obscure words, spell and define each term the first time you use it.

For more tips on accessible presentations, check out the Web Accessibility Initiative's presentation guidelines.