Firefixia: An Accessibility Web Browser Customization Toolbar for People with Dyslexia
Vagner Figueredo de Santana, Rosimeire de Oliveira, Leonelo Dell Anhol Almeida, Marcia Ito · 2013 · Proceedings of the 10th International Cross-Disciplinary Conference on Web Accessibility (W4A) · doi:10.1145/2461121.2461137
Summary
This paper presents Firefixia, a Mozilla Firefox browser extension toolbar designed to help people with dyslexia customise the presentation of web content according to their individual preferences. The authors note that while web accessibility efforts have traditionally focused on visual disabilities, dyslexia — which affects 15-20% of the population according to the International Dyslexia Association — receives comparatively little attention. WCAG 2.0 mentions dyslexia in only one success criterion (3.1.5 Reading Level). Since there is no universal profile for people with dyslexia, the authors argue that end-user customisation is a particularly appropriate approach. Firefixia was built by analysing 40 dyslexia-specific accessibility guidelines from a prior survey and selecting 11 that could be implemented as browser-side presentation adjustments. The toolbar allows users to modify: font size, font type (switching to monospaced sans-serif), text alignment (avoiding justified text), line spacing, character spacing, background colour (avoiding pure white), text colour, link colour, visited link colour, line width (avoiding wide columns), block element borders, and italic removal. All features are presented as icon buttons with no text labels to ease use.
Key findings
Four adults with diagnosed dyslexia (aged 18-62, all male) tested Firefixia while performing tasks on a Brazilian government tax website. All participants rated the toolbar positively (good to really good) across understanding, ease of use, and utility. The most valued customisation features were text size (mentioned by all 4 participants), text alignment (4 mentions), and link/visited link colour (3 mentions), followed by line spacing (2 mentions) and background colour (1 mention). Font type was rated least useful by 2 participants. Participants revealed distinctive coping strategies for reading on screen: one placed his finger on the monitor to track the line being read, another used the mouse pointer as a reading guide. These workarounds highlight the need for line-tracking features. One participant relied exclusively on Google search rather than site navigation, saying "anything I do, I search in Google. I do not search in the websites." Another participant found CAPTCHAs with numbers particularly difficult due to his number interpretation difficulties. Two participants asked for copies of the toolbar to use at home, indicating genuine perceived value.
Relevance
This research highlights an underserved population in web accessibility: people with dyslexia. For web developers and designers, the key practical takeaway is that three simple presentation features — adjustable text size, non-justified text alignment, and distinguishable link colours — were consistently identified as the most impactful by users with dyslexia. These are straightforward CSS properties that any website could offer as built-in customisation options without requiring a browser extension. The study also reinforces that WCAG compliance alone is insufficient for cognitive accessibility; only one WCAG 2.0 success criterion explicitly addresses dyslexia. The participants' coping strategies (finger tracking, mouse-pointer reading, defaulting to Google instead of site navigation) reveal how people with dyslexia adapt to inaccessible designs in ways that conformance testing would never detect. For organisations, this underscores the importance of offering presentation customisation and ensuring clear, well-differentiated navigation structures.
Tags: dyslexia · web accessibility · browser extension · customization · assistive technology · reading accessibility · user testing · cognitive accessibility
Standards referenced: WCAG 2.0