Accessibility Checks for HTML Slide Decks Before You Share Them as PowerPoint

More and more presentations start life as HTML. Developers build them with reveal.js or Slidev, designers export them from AI tools, and teachers write them in simple web editors. When those decks need to be shared with a wider audience, they are often turned into PowerPoint files so that anyone can open them. That is a good moment to check accessibility, because problems that are easy to fix in HTML can become harder to spot once the slides are a set of images or shapes in a PPTX.

This checklist focuses on the things that matter most for people using screen readers, people with low vision and people who read slides on small screens.

1. Check colour contrast

Low-contrast text is the most common accessibility problem in slide decks. Light grey text on white, or pale text over a photo, may look stylish on a large monitor but becomes unreadable on a projector or phone. Aim for a contrast ratio of at least 4.5:1 for body text and 3:1 for large headings. Browser developer tools and free contrast checkers can test this in seconds while the deck is still HTML.

2. Use a sensible font size

HTML decks sometimes rely on viewport units that shrink text on smaller screens. Before converting, view each slide at a typical 1280 by 720 size and make sure body text is still comfortably large. A good rule of thumb is that nothing important should be smaller than about 24 pixels at that size.

3. Don't rely on colour alone

Charts that use only red and green to show good and bad results are hard to read for many colour-blind viewers. Add labels, icons or patterns so the meaning survives even in greyscale. Try printing one slide in black and white as a quick test.

4. Write meaningful slide titles

Every slide should have a clear, unique title. Screen reader users often navigate a presentation by its titles, and readers skimming a shared file use them the same way. "Results" repeated on five slides is less helpful than "Q3 Results: Sign-ups up 18%".

5. Prepare alt text and a text summary

Images and charts need short descriptions. In HTML you may already have alt attributes, but depending on how a deck is converted, that text may not carry over into the final file. Keep a simple document with a one-line description of each important image and the key point of each slide. You can paste these into the speaker notes or share the summary alongside the PowerPoint file.

6. Understand what your converter produces

Converters work in different ways. Some rebuild slides as editable text boxes, while many browser-based tools capture each slide as a high-fidelity image so that the layout looks exactly like the original. A tool like HTML to PPTX focuses on keeping the visual design faithful, which is great for sharing and presenting. The trade-off is that slide content may not be selectable text, so a screen reader cannot read it directly. That is exactly why the text summary in step 5 matters: it gives everyone access to the content, whatever form the slides take.

7. Check animations and motion

HTML decks often include transitions, parallax effects or auto-playing animation. These rarely survive conversion in their original form, and they can also cause discomfort for people sensitive to motion. Decide which slides genuinely need a build sequence and, if necessary, split them into separate static slides that show each step.

8. Mind reading order on complex layouts

When a slide has several columns, callouts and floating boxes, the visual reading order is not always obvious. Simplify where you can. One main message per slide, read top to bottom and left to right, is easier for everyone.

9. Include links as readable text

If a slide refers to a website, write the address in a short readable form, such as example.com/report, rather than only hiding it behind a "click here" button. Links may not remain clickable after conversion, and printed handouts certainly will not have them.

10. Test with a real reader

Finally, ask a colleague to open the converted file on a laptop and a phone. Can they read every slide? Do the speaker notes or summary explain the charts? Five minutes of feedback often reveals issues that automated checkers miss.

Accessibility is part of good sharing

Converting an HTML deck to PowerPoint is usually about reaching more people: managers who live in Office, clients behind strict IT policies, students on school laptops. Taking a few minutes to check contrast, titles, alt text and summaries makes sure that wider audience can actually use what you share.