The settings that actually change how a page feels
Line length is the setting nobody adjusts and everybody feels: aim for about 60 to 75 characters per line. Longer lines make your eye lose its place on the return sweep, which reads as "I keep re-reading the same sentence" rather than as a layout problem. On a phone, that means leaving the default; on a tablet or desktop, it means margins.
Then raise line spacing before you raise font size. Air between lines does most of the work people expect from a bigger typeface, and it costs you less text per screen. Raise size after, until you are no longer leaning toward the page.
What the dyslexia-font evidence says
Controlled studies have not found that dyslexia-specific fonts improve reading speed or accuracy compared with ordinary, well-set text. What helps in those studies is usually the thing bundled alongside the font: larger type, more spacing, shorter lines. If OpenDyslexic makes you want to read, use it — preference is a legitimate reason, and it is a different claim from "it works".
A starting configuration
| Setting | Start at | Why |
|---|---|---|
| Typeface | The device default serif or sans | Familiar shapes need no learning |
| Size | One or two steps above default | Stop leaning toward the page |
| Line spacing | The next step up | Cheapest legibility win there is |
| Line length | 60–75 characters | Protects the return sweep |
| Margins | Wider than default | Shortens lines without shrinking type |
| Justification | Left-aligned, not justified | Avoids rivers of white space |
| Theme | Match the room's light | Contrast comfort, not ideology |
Bionic reading and bold-first-letters modes
Several apps bold the first letters of each word. Independent testing has not shown a reliable speed or comprehension benefit for bionic reading. It is free to try and harmless; just do not buy a subscription for it. The full look at the evidence →
Where to change these
E-readers give you the deepest control — the Kobo Libra the deepest of the ones we have scored. Read-it-later apps like Matter let you set type once for every article you save. Browsers ship a reader mode that fixes most badly-set websites in one keystroke.