Reading support tools: text to speech, dyslexia aids and what actually helps
Text-to-speech, reading rulers, font choices and summarisation tools, sorted by what the evidence supports and what is marketing.
Assistive technologyPublished
Reading support is a crowded market with an unusually wide gap between what is sold and what holds up. Sorting it is worth twenty minutes because the tools that work are mostly free and already installed.
Text to speech
The single most useful category, and the one with the least controversy. Having text read aloud while following it visually reduces decoding load and frees working memory for comprehension. It helps people with dyslexia, people with acquired reading difficulties, people reading in a second language, and people who are simply tired.
Every major platform has it built in: Speak Screen and Spoken Content on iOS and macOS, Select to Speak on Android, Read Aloud in Edge and in Word, Immersive Reader across Microsoft products. Browser extensions add it elsewhere. Paid products mainly add vocabulary tools, study features and voice quality, not the core function.
This is distinct from a screen reader, which is a full navigation interface for people who cannot see the screen. Text to speech reads content to someone who is looking at it.
Visual adjustment
Reading rulers, line focus modes, adjustable line and letter spacing, column width limits, off-white backgrounds. These are cheap, built into Immersive Reader and similar tools, and many readers report a clear benefit.
The mechanism is contested. Coloured overlays in particular have a long history of strong claims and weak trials, and the research does not support the idea that a specific colour corrects a visual deficit underlying dyslexia. What is well supported is that increased spacing and reduced line length improve reading speed for struggling readers generally.
The practical position: offer the adjustment, let the reader choose, do not sell it as a treatment. On your own site, that means not fighting the user’s settings. Respect prefers-reduced-motion, do not disable zoom, use relative units so text scales, and make sure your layout survives a 200 percent text increase, which is WCAG criterion 1.4.4.
Fonts
Fonts marketed specifically for dyslexia have not held up well in controlled comparison. Multiple studies have found no reliable advantage over a well-set standard sans-serif, and some found readers were slower with the specialised face.
What does help is unremarkable: a clean sans-serif at a comfortable size, generous line height, left alignment rather than justified text, and enough contrast. That is the same advice as the easy-to-read layout rules, arrived at independently.
Summarisation and rewriting tools
Language models will now summarise or simplify any text on demand, and for a reader facing a wall of administrative prose that is genuinely useful.
Two cautions apply. The output is not verified, and in exactly the documents where simplification matters most, benefits letters, medical information, contracts, a confident wrong simplification is worse than the original. And a machine simplification is not easy-to-read in the standard’s sense, because it has not been through the review step by people with intellectual disabilities. Use it as a personal reading aid, not as a publishing method.
What to do on your own pages
Most reading support fails because the page fights it, not because the tool is bad.
Publish content as HTML rather than as a PDF wherever there is a choice, because reading tools handle a web page far better than a downloaded document. Use real headings so a reader can skim. Keep line length in the region of sixty to seventy-five characters. Do not put text inside images. Give links descriptive text. Provide a plain-language summary at the top of anything long, which helps every reader and costs one paragraph.