Accessible presentation checklist

An accessible presentation passes two sets of checks. On the slides: text contrast of at least 4.5 to 1, large plain type, a distinct title on every slide, descriptions for images and charts, nothing that relies on colour alone and nothing that flashes. In the delivery: every relevant visual described out loud, clear and unhurried speech, a microphone used every time, and materials shared in a format people can adapt. The table under this article lists twenty checks with the standard behind each and how to test it.

The standards come from two places. WCAG 2.2 was written for web content, but its contrast, colour and text alternative rules apply directly to slides. The W3C’s guide to making events accessible covers what WCAG does not: the speaker, the room and the handouts.

Contrast and colour

Contrast is the check most decks fail, and the easiest to measure. WCAG 2.2 success criterion 1.4.3 requires a contrast ratio of at least 4.5 to 1 between text and background, and 3 to 1 for large text, which the understanding document defines as 18 point, or 14 point bold. Criterion 1.4.11 extends the 3 to 1 minimum to graphical objects that carry meaning, such as chart bars and icons.

Test on the real colours with a contrast checker, which gives the ratio for any pair of colours, then add a margin for the room. A projector in a bright room lowers contrast further, so a pale grey caption that scrapes past 4.5 to 1 on a laptop can disappear on the wall. The safety training presentation uses a high contrast cover built to read from the back of an induction room, which is the right instinct for any deck shown on a projector.

Never let colour carry meaning alone, which is criterion 1.4.1. The compliance training deck gets this right in its gift matrix: each cell says Accept, Accept and register, or Decline in words, so the table works for someone who cannot tell its colours apart. A quick test is to view a slide in greyscale; anything that stops making sense needs a label.

Type size and amount of text

Microsoft’s accessibility guidance for PowerPoint recommends 18 point or larger, sans serif fonts and sufficient white space. Treat that as the floor for the smallest text on your busiest slide, not an average.

The W3C adds the point about quantity: it is hard for many people to read text and listen at the same time, so limit the text on each slide and put extra detail in a handout. Fewer words also let you set them larger, which solves two problems at once.

Choose a family with even stroke thickness. The W3C notes that fonts with thin parts of letters are harder to read from a distance, and decorative faces harder still.

Titles, reading order and descriptions

Give every slide a distinct title. Microsoft explains why: people who are blind, have low vision or have a reading disability use slide titles to navigate, skimming or listening to the list of titles to find the slide they want. Twelve slides titled “Results” are one slide as far as that list is concerned.

Describe every meaningful image and chart in text, which is WCAG criterion 1.1.1. In a presentation file that means alt text where the tool supports it, and in every case it means a caption or a spoken description. A chart’s description is its finding and its key numbers, not “bar chart”.

Check the reading order too. A screen reader follows the order objects were added, not where they sit, so a slide that looks right can be read bottom to top.

Motion and media

Keep transitions simple. The W3C asks presenters to consider whether motion makes the information easier to understand or is unnecessary, and warns that some movement distracts people and can make some people ill. WCAG criterion 2.3.1 is absolute on flashing: nothing should flash more than three times in any one second. Check embedded videos and animated images as well as your own transitions.

Caption every video you play, under criterion 1.2.2, and play it once with the sound off to be sure the captions carry it.

Delivery: what you say matters as much as the slides

The W3C’s guidance for speakers is where most accessible decks become inaccessible talks. Its core instruction is to describe all relevant visual information: say what is on each slide, text and graphics, without necessarily reading it word for word. “As you can see on this chart” excludes everyone who cannot see the chart.

The company profile presentation is a good deck to practise this on, because every slide carries something concrete to say. Its numbers slide gives three figures, each with a sentence underneath, which reads aloud naturally: 240,000 meals a week, 96 million dollars in revenue, 412 people employed. Its history slide is seven dated steps, which can be spoken as a sentence per step in order.

The rest of the W3C’s delivery checklist is short and practical: speak clearly and not too fast, always use the microphone, start with an overview and end with a review of the main points, keep the slide design consistent, and give captioners, interpreters and attendees who need them the materials in advance.

Handouts and shared files

The W3C recommends offering material in formats people can adapt, such as word processing files or HTML, and avoiding providing material only in formats users cannot adapt, including PDF. A PDF made from images of slides is the least adaptable of all, because a screen reader has no text to read.

Send it before the session where you can. People who use a screen reader, magnification or a second language can read ahead and follow the talk rather than chase it, and captioners and interpreters can learn the names and acronyms they will hear. Afterwards, send the same file again with any changes, so nobody is working from an old copy.

Offer the content as text as well. The simplest version is a document with each slide’s title, its main points and a description of each chart, which also makes a better handout than the slides for most readers.

Common mistakes

• Light grey text for captions and footnotes that fails contrast.
• Red and green as the only difference between good and bad in a chart.
• Duplicate slide titles that make navigation by title useless.
• “You can read it on the slide”, which excludes anyone who cannot.
• A PDF as the only handout.

Build it

In the slide builder, the theme panel sets colours for the whole deck and each slide can switch between four colour modes: spectrum, matching, outline solid and dark. Check contrast in each mode you use, not only the first. The fonts tab applies one of 27 families, 18 of them sans serif, or the theme default, across every slide; the presentation fonts page lists them, and what a presentation theme is explains why setting this once matters. Sizes come from a 19 step type ramp rather than a typed number. The transitions panel has eight options, one of which is None.

Know the export formats before you rely on them for accessibility. The PDF export places an image of each slide on each page, so its text is not selectable, and the plain PowerPoint export is also a picture per slide. The editable PowerPoint export rebuilds text, lists, tables and charts as native objects, which is the adaptable option; it is a paid feature. Speaker notes are not included in any export, so a text handout has to be written separately. The guide to changing your presentation’s theme, fonts and colours covers the settings, and how to present data in slides covers labelling charts so the finding does not depend on colour.