Blog · Online Learning
Dyslexia and online courses — making Coursera, Udemy, and edX easier to read
Online learning platforms have made education more accessible in dozens of ways. For dyslexic readers, though, they have quietly inherited every typographic mistake of the web: cramped default fonts, tiny text, long lines that run edge to edge, and no settings to change any of it. This guide covers what each major platform gives you out of the box, and the browser-level changes that override whatever the platform has decided to do.
Why MOOC platforms are particularly taxing for dyslexic readers
The problem is not unique to any one platform. It is structural. Most online courses mix three reading contexts in rapid succession: video lecture captions, dense written readings (often sourced from academic papers or textbooks), and text-heavy quizzes or graded assignments. Switching between these modes continuously adds cognitive overhead on top of the reading itself. For a dyslexic learner, that means fatigue arrives faster and comprehension starts to slip before the session should logically be over.
The other structural issue is line length. On a full-size monitor, Coursera and edX often render their reading panes at widths north of 800 pixels of actual text — far beyond the 60 to 75 characters per line that most readability research points to as comfortable. Dyslexic readers, who are already managing more regressions (backwards eye jumps) per line than the average reader, feel that extra width more acutely. A longer line means more chances to lose your place when the eye tries to return to the start of the next line.
None of this is new information to accessibility researchers. The British Dyslexia Association's style guide has recommended constrained line lengths, generous line spacing, and sans-serif body fonts since at least the early 2010s. Online course platforms have been slow to apply it.
What each platform gives you by default
Coursera
Coursera's reading material lives in two places: HTML course pages (lecture supplements, reading assignments) and embedded PDFs. The HTML pages use a system sans-serif at a reasonable base size, but the line spacing is tight and the text column often stretches the full width of the content pane. There is no built-in font selector, size slider, or line-spacing control. Coursera does have auto-generated captions on all video lectures, and you can open a transcript alongside a video — which is worth doing, because you can then apply your font preference to the transcript text with a browser extension.
Udemy
Udemy is more video-heavy than Coursera, with shorter reading burdens overall. Where you will hit significant text is in the Q&A section below each lecture, in instructor-supplied resource files (PDFs, slide decks, cheat sheets), and in any course that teaches a text-heavy subject like writing, law, or programming via documentation. Udemy has closed captions on most courses, though quality varies by instructor. There is no font or spacing control anywhere in the interface.
edX
edX (now part of 2U) skews toward university-level courses and carries the typographic habits of academia with it. Reading assignments link out to journal articles or render dense HTML text at small sizes with serif or narrow sans-serif fonts. Problem sets and graded exercises are text-heavy. edX has invested in screen-reader compatibility and keyboard navigation, which is valuable but separate from the font and spacing issues a dyslexic reader faces. There is no built-in text customisation.
Khan Academy
Khan Academy uses shorter explanatory paragraphs, more visual diagrams, and a generally lighter reading load than the three above. It is the friendliest of the major free platforms for dyslexic readers by default, partly because its content is designed for younger audiences and so tends toward clearer, more direct language and shorter sections. That said, the text is still small and tightly spaced on many exercises, and there is no font customisation available.
The fix that works everywhere: override the font in Chrome
Since none of these platforms offer built-in font settings, the practical solution is to work at the browser level. A Chrome extension that applies a dyslexia-friendly font to every website sidesteps whatever the platform has chosen. The extension does not know or care whether it is on Coursera or anywhere else — it just replaces the font on every text element it can reach.
Changing the font on any website used to require editing a user stylesheet, which was fiddly. Today, LexiFont handles it with a single toggle. Install the extension, pick a font, and every reading pane on every course platform immediately renders in that font.
Which font is worth a moment of thought. The most commonly recommended choices for dyslexic adult readers are OpenDyslexic, Lexend, and Atkinson Hyperlegible. A full comparison of what each one does differently is in the best fonts for dyslexia 2026 guide. The short version: if letter reversals (b/d, p/q) are part of your experience, OpenDyslexic is worth trying first. If you want something that looks closer to normal while still being easier to track, Lexend is a strong default. Both are available in LexiFont Pro; OpenDyslexic is free.
The difference at the character level is subtle. At the paragraph level — once you have been reading for twenty minutes — it is not.
Spacing: the change that matters as much as font choice
Font choice gets most of the attention, but line spacing and letter spacing make a substantial difference independently of which typeface you use. The British Dyslexia Association recommends a line height of at least 1.5 times the font size for dyslexic readers; the European Dyslexia Association points to 1.8 as a comfortable target for dense academic text.
Most course platforms render at 1.3 to 1.4, which is technically readable but actively tiring over a long session. LexiFont Pro lets you dial in line height and letter spacing per-site, so you can set Coursera's reading pane to your preferred spacing and leave it there across sessions.
The other spacing lever worth using is the browser's zoom. On most platforms, pressing Cmd/Ctrl + once or twice increases the font size without breaking the layout, and larger text means the proportional spacing also increases. This is free and immediate — worth doing before anything else.
Background colour and contrast
Most MOOC platforms default to black text on white, which gives maximum contrast in terms of luminance ratio but is actively uncomfortable for readers with visual stress. If white backgrounds cause the text to appear to "shimmer" or if you find yourself squinting at bright white between words, a warmer or slightly tinted background reduces that effect.
The options for adjusting background colour are more limited than font options. The cleanest approach is to enable your operating system's Night Mode or True Tone setting, which warms the entire display rather than any one website. This is a coarser change than applying a specific background colour to text, but it requires no per-site configuration. Some readers find the cream-tinted display sufficient; others find the yellow warmth of Night Mode at high intensity distracting and prefer a grey rather than a warm tint.
If you want site-level control, a browser extension that applies a custom CSS background colour can target specific platforms.
Video content: captions and transcripts
Video lectures are, for many dyslexic learners, the more accessible part of online courses precisely because they offload reading onto listening. The problem arises when the captions are hard to read — small, displayed in a serif font, or positioned against a low-contrast background.
On Coursera and edX, captions are displayed in the video player's built-in style. You cannot directly change the caption font with a browser extension, because captions inside a native video player are rendered by the browser rather than the page HTML. However, both platforms offer a transcript view alongside the video, where the spoken text is rendered as HTML text that you can style with a font extension. Opening the transcript and following along there, rather than reading on-screen captions in the video, is a practical workaround that gives you full control over how the text looks.
For courses hosted on YouTube (which many Udemy and Khan Academy courses use for their video players), YouTube has its own caption accessibility settings. In YouTube's player settings, under Subtitles/CC, you can change the caption font, size, and background opacity. Larger, high-contrast captions on YouTube make a meaningful difference for extended viewing. The YouTube and dyslexia guide covers this in more detail.
Quizzes, assignments, and text-heavy exercises
The reading load in an online course is not just in the lectures and readings. Quizzes present their questions as styled text inside the platform's own UI, and peer-reviewed assignments on Coursera require reading other students' long-form submissions. These surfaces often have smaller font sizes and tighter spacing than the main reading content, and because they are interactive elements rather than static text, some font extensions have difficulty reaching them.
A few practical adjustments help here. First, increase browser zoom before you start a quiz — pressing Ctrl/Cmd + once or twice is usually enough, and most quiz interfaces stay functional at 110% or 120% zoom. Second, if an assignment asks you to read a long peer submission, copy the text into a simple editor (even a plain text file) so you can read it in your own font and layout. This takes thirty seconds and can substantially reduce the fatigue on a long marking session. Third, break quiz sessions into smaller chunks if the platform allows it — checking out mid-quiz is often not possible, so plan to complete a quiz in one go and leave time around it.
Practical sequence for any online course session: open your course page, press Ctrl/Cmd + to reach a comfortable zoom level, confirm your font extension is active, then open the transcript view alongside any video before you start watching. Those three steps take under a minute and cover most of the reading-comfort issues the platform itself does not address.
Text-to-speech as a complement, not a replacement
Some dyslexic learners find that following along with text while listening to it read aloud is more effective than either reading or listening alone. This dual-coding approach — seeing the words and hearing them simultaneously — can improve comprehension and retention, particularly on dense academic text. A text-to-speech Chrome extension can read the text on any course page aloud as you follow along.
The practical limitation is that TTS does not work reliably inside video players or on interactive quiz elements. It works well on static reading pages, course introductions, and graded essays. For anything inside a video player, the transcript view is a better entry point.
A broader approach: setting up for online learning
If online courses are a substantial part of how you are learning — working through a certification, re-skilling, or supplementing university study — the per-platform tweaks above are worth complementing with a fuller laptop setup. The dyslexia tools for students guide covers PDF readers, note-taking apps, and system-level settings that carry across every platform you use. If you are specifically studying research papers or academic sources as part of your course, there are additional font and layout steps that apply to PDF-heavy reading that are worth doing separately.
The same underlying principle applies across all of them: the platform will not do this for you, but the browser can. A font extension installed once applies everywhere, costs no ongoing effort, and lets you actually concentrate on the material rather than on fighting the typography.
LexiFont Pro — Lexend, Atkinson Hyperlegible, line spacing controls, $14.99 one-time
Further reading
- Best fonts for dyslexia in 2026 — a research-first guide
- Line spacing and letter spacing for dyslexia — what the research says
- Background colours for dyslexia — cream, blue, or grey?
- Dyslexia tools for university students — laptop setup guide
- Reading research papers with dyslexia — fonts and layout that help
- Reader mode vs reading extensions — which is better for dyslexia?