My Day 2 goal was to make London’s public transport data usable and meaningful to someone navigating the dashboard entirely through a screen reader. The key focus was to identify which boroughs are underserved by step-free stations, and allow for filtering based on practical features like toilets, lifts, and proximity to attractions.
We worked with the London Accessibility Dataset, using Attraction Data sheets to produce a borough-level summary.
To make the dashboard screen reader-friendly, I followed these core principles:
- Semantic text ordering: Every text object was placed with a logical tab order in mind, ensuring screen readers relay information clearly and in the right sequence.
- Alt text on visuals: All visuals and KPIs were tagged with descriptive alt text so their meaning could be conveyed without relying on visuals.
- Keyboard navigation: The dashboard includes clear instructions for how to move between sections using only the keyboard.
- No hidden tooltips: Key insights weren’t locked behind hover-only interactions. If it couldn't be read aloud, it didn’t belong.
Key considerations and recommendations I gathered when using PowerBI to create a screen-reader friendly report are as follows:
Alt Text
•You can provide alt text for any object on a Power BI Desktop report by selecting the object (such as a visual, shape, and so on) and in the Visualizations pane, select the Format section, expand General, scroll to the bottom, and fill in the Alt Text textbox. The Alt Text textbox has a limit of 250 characters.
•Recommended tip: Begin Alt text with “. Text” because the alt text does not come first and the narrator doesn’t pause between what’s prior and the Alt text.
Tab Order
•Tab order is very important when using a screen reader as this depicts the order in which the narrator will read the report objects.
•It is important to note that all decorative aspects such as images, should be hidden so the narrator does not read them out.
Bonus Considerations
•Shift + ? = Will bring up a list of potential commands for someone navigating the screen reader using the keyboard.
•When using screen readers with Power BI Desktop, you'll have the best experience if you open your screen reader before opening any files in Power BI Desktop. (for larger reports).
Ultimately, I built the interactive, screen-reader friendly report, publishing it to the Power BI Service. The final product is fully navigable with a screen reader, allowing users to move through filters, charts, and summaries while gaining the same insights as any other user.
