Typeface Legibility

A meta-analysis, published as an open-access book in 2022 under the title The Legibility of Serif and Sans Serif Typefaces: Reading from Paper and Reading from Screens, looked at existing literature regarding the relative legibility of different typefaces as presented in different mediums.

Times New Roman is a typeface, while a font is a specific treatment of a typeface, like “Times New Roman, size 14, bold.”

Some typefaces (including Times New Roman) have little lines on their endpoints, and these lines are called serifs. A serif typeface has serifs, a sans-serif typeface (like Arial) does not.

There are other typeface styles that straddle the line between serif and sans-serif, but the primary dichotomy in the English-language typeface world is faces with serifs and those without.

There’s a common belief, based mostly on anecdote, but also a bit of older research, that serif typefaces are easier to read because their shapes are more legible, possibly because the serifs help guide the eye from one character to the next.

It’s also commonly believed that serifed faces tend to be more legible in smaller sizes and on paper, while sans-serifs are more ideal for screens, like those on our phones and laptops.

This meta-analysis found, however, that the majority of existing work in this space demonstrates no difference in legibility between these two typeface categories, and that the research that does seem to show differences between them usually suffers from methodological issues.

It also found that previous research that both holds up and has no major methodological flaws actually indicates that the big difference in terms of legibility and intelligibility is not between serif and sans-serif categories, but between individual typefaces, some of which are just a lot more readable than others (and this seems to be true across all mediums).

Some typefaces have difficult to read lower-case a’s, some have better (in the sense of being easier to parse in different contexts) upper-case D’s, and so on.

Rather than supporting the assertion that serif or sans-serif typefaces will tend to be more intelligible on paper or screens, then, the existing research actually says that there are more and less legible faces in both categories. People who design websites and books should thus use both types if they want to, while avoiding faces with confusing, similar-looking letters when possible (and adjusting the spacing, not the typeface, if they’re optimizing for people with visual impairment or dyslexia).