legibility

noun

1. (countable, uncountable)The property of being legible or easily readable.

   “The legibility of this text is questionable: half the people asked said it was almost illegible, but the other half said it was easy to read.”

   “The legibility of a type-face is very largely dependent on the absence of similarity between those characters of pairs or triplets which are the most easily mistaken for one another.”