Slide Accessibility

Slide Accessibility

When to use

Use this skill when a deck goes to a public body, a bank, a healthcare or education client, anyone procuring under an accessibility standard, or any audience that includes a screen-reader user. Also use it before a deck is published to a website, because a published .pptx or its PDF inherits every defect. Do not use it as a general design pass; contrast and reading order are correctness problems, not taste problems, and brand-compliance-auditor covers the rest.

What it does

It runs the deck against the checkable accessibility requirements, fixes them in the file rather than in a separate document, and produces a defect list with what was changed. The output is a remediated deck plus an audit trail a procurement team can accept.

Method

1. Know which standard you are held to. In the United States, Section 508 incorporates WCAG 2.0 Level AA; in Europe, EN 301 549 references WCAG 2.1 Level AA and underpins public-sector procurement. Most contracts name WCAG AA. Ask which, and write the answer at the top of the audit.

2. Give every slide a unique title. It is the primary navigation handle: a screen reader announces it, and Outline view and slide-jump tools use it. Every slide needs one and no two should be identical — three slides called "Agenda" defeat the point. Where the design carries no visible title, hide the placeholder rather than deleting it: with the Accessibility Checker open, the Accessibility tab's Slide Title menu offers Add Slide Title and Hidden Slide Title, which puts a real title off the visible canvas.

3. Write alt text that carries the information, and mark the rest decorative. Right-click an object and choose Edit Alt Text, or use the Accessibility tab. What matters:

• Describe what the image means here, not what it depicts. A revenue chart's alt text is the finding — "Revenue grew from £12m to £31m over four years, with the step change in FY23" — not "bar chart". Do not open with "image of"; the screen reader already says so.
• Decorative rules, textures and brand furniture get the Mark as decorative checkbox, which removes them from the reading order. That matters as much as describing content.
• A screenshot of a table is invisible. Rebuild it as a real table.
• Alt text on a group is read and its members are skipped, so give a composite diagram one good group-level description rather than eleven fragments.

4. Fix the reading order, and know which pane you are in. Two tools, and they run in opposite directions:

• Reading Order Pane (Review > Check Accessibility, then the Reading Order Pane button on the Accessibility tab) lists objects top to bottom in reading order — the top item is read first. Windows desktop only; it is not in PowerPoint for the web or on macOS.
• Selection Pane (Home > Arrange > Selection Pane) lists the same objects in z-order, which is the reverse — the bottom item is read first. This is the single most common remediation mistake: a deck "fixed" in the Selection Pane top-down comes out backwards.

Order should follow the argument: title, then exhibit or body, then source line and footnotes. Re-check after any layout change, because a newly inserted shape lands at the front.

5. Check contrast against the real numbers. WCAG AA requires 4.5:1 for normal text and 3:1 for large text, where large means 18 pt or larger, or 14 pt bold or larger. Meaning-bearing non-text elements — chart series, an icon that is the only label — need 3:1. The built-in checker flags some contrast problems but misses text over a photograph, a gradient or a semi-transparent panel, so sample the actual pixel behind the text. Where a brand colour fails, do not invent one: use the palette's approved dark tint, or put the text on a solid panel.

6. Never encode meaning in colour alone. A red bar and a green bar mean nothing to a colour-blind reader or in greyscale print. Add a direct label, pattern or symbol alongside the colour, and test by exporting a slide in greyscale.

7. Build tables as tables. A grid of aligned text boxes looks like a table and exports as loose text. Use a real table object, tick Header Row in Table Design > Table Style Options, and keep it rectangular: no merged or split cells, no blank rows used as spacing, no nested tables. PowerPoint tables cannot express column and row scope, so a table that needs both is a sign it should be split into two.

8. Handle media and motion. Video needs captions: select it and use Playback > Insert Captions, which accepts a WebVTT (.vtt) file. Audio needs a transcript, which can live in the notes. Nothing may flash more than three times per second. Avoid autoplay, and avoid animations that carry information the static slide does not — a build that reveals the punchline is lost in the exported file.

9. Make links say where they go. "Click here" and a bare URL are both useless read aloud. In Insert > Link, put a meaningful phrase in Text to display and add a ScreenTip where the destination is not obvious.

10. Run the checker, then export correctly. Review > Check Accessibility sorts findings into Errors, Warnings and Tips; work Errors first and tick Keep accessibility checker running while I work. It is a floor, not a ceiling — it cannot judge whether alt text is good. On export, leave Document structure tags for accessibility on (see pptx-export-and-pdf); an untagged PDF discards everything above.

Inputs

• The deck, and the standard being applied.
• The brand palette with hex values, so contrast is computed against approved colours.
• Whether the deliverable is the .pptx, a PDF, or both.
• Any embedded media, and whether captions or transcripts exist.

Output format

• The standard applied, stated at the top.
• A defect list by slide: issue, severity, and the fix made.
• Contrast as measured ratios against the 4.5:1 and 3:1 thresholds, naming failing pairs.
• Reading order changes, with the pane used.
• Anything that could not be remediated in PowerPoint, and why.
• The checker's final state and the export settings used.

Example

Input: a 24-slide programme update for a public-sector client, contracted to WCAG 2.1 AA.

Output:

• Standard: WCAG 2.1 AA (EN 301 549).
• Titles: 24 of 24 titled; slides 3, 11 and 20 use hidden titles because the design is full-bleed. Three duplicate "Progress" titles disambiguated.
• Alt text: 31 objects described, 14 decorative motifs marked decorative, chart alt text on slides 6, 9 and 14 rewritten to state the finding.
• Reading order: corrected on 9 slides in the Reading Order Pane. Slide 17 had been "fixed" bottom-up previously and was fully reversed.
• Contrast: brand mid-grey #8A8F98 on white measured 2.9:1 at 12 pt and fails; replaced with #5A6069 at 4.9:1. Amber chart series at 2.1:1 darkened and direct-labelled.
• Colour alone: RAG status on slides 8 and 15 given text labels.
• Tables: slide 12's text-box grid rebuilt as a real table with Header Row; slide 19's merged header cells split.
• Media: the embedded video captioned from a supplied .vtt.
• Export: PDF with structure tags on. Checker reports zero Errors, two Tips retained deliberately.