Optimal Line Length

The 66-character myth and reality.

Saccades and Doubling

If a line is too long, the eye struggles to find the start of the next line (doubling). If too short, the eye bounces too frequently.

Eye-tracking research indicates that line lengths exceeding 80 characters cause doubling in 40% of readers.

Common Line Length Mistakes

MistakeImpactSolution
100% width text on desktopUnreadable walls of text.Constrain max-width to roughly 65ch.

Character Count Estimator

FAQ

Does font size change the optimal length?

Yes, but the metric should always be calculated in 'ch' (characters) rather than pixels.