Field note · JZ-003 · Perception ·
Which is read faster, short lines or long lines?
- The guess
Short lines look easier: calm and readable.
- What the research found
Reading from screen, text set at 100 characters per line was read faster than text at 25. But people rated about 55 characters per line as easiest to read, and a later study found 55 was understood better than 100. Speed, understanding and preference point in different directions.
- Why
Every new line is a jump back to the left edge, so long lines mean fewer jumps and less scrolling. Faster is not the same as clearer.
- What to do
- Decide what the text is for. For skimming and scanning, a wider measure is fine; for study and understanding, aim for about 55 characters per line.
- Set the measure in characters (for example max-width in ch units), not in pixels, so it holds across type sizes.
- Test with your own content, typeface and devices.
- What not to do
- Pick a line length by feel alone. What feels easiest is not what is read fastest or understood best.
- Present one line length as best for every purpose.
- Limits
- These studies used one typeface and size on desktop screens; mobile was not tested.
- Speed, understanding and preference were measured separately and can conflict.
- Status: the comprehension finding for 55 characters is being checked in the full paper; this skill ships when it is confirmed.
- Sources
Dyson, M. C. & Kipping, G. J. (1998). The effects of line length and method of movement on patterns of reading from screen. Visible Language, 32, 150–181.
Dyson, M. C. & Haselgrove, M. (2001). The influence of reading speed and line length on the effectiveness of reading from screen. International Journal of Human-Computer Studies, 54, 585–612.
Dyson, M. C. (2004). How physical text layout affects reading from screen. Behaviour & Information Technology, 23(6), 377–393.
Also as markdown for your AI: softwarebehavior.com/notes/jz-003.md
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