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Adjustable Line Spacing

When using the CISL reader, you can adjust the space between lines of text. Readers have the freedom to have lines of text closer together or further apart, depending on their personal preference. One user tester said, "When I read I skip lines, so it’s really helpful for me to have spacing between lines."

Try out different line spacing options in Clusive!

Adjustable line spacing image: Two images of the same article within the CISL reader environment are shown side-by-side. The article in the image on the right has more space between lines of text, compared to the article in the left image. Above the two images a line of text reads “More or less space between lines?” with two arrows, one pointing to each image.

Readers can adjust the spacing between lines of text. Do you prefer the version with less or more space between lines?


The research findings on adjustable line spacing are mixed. Some studies report that larger line spacing improves reading speed and accuracy for adolescents and adults with dyslexia:

  • A study of 74 children with dyslexia, ages 8 to 14, found that extra-large letter and line spacing improves text reading speed and accuracy.
  • A study of 22 individuals with dyslexia, ages 13 to 37, found that the narrower the spacing between lines, the longer participants took to read a passage. Participants’ preferences were split between single line spacing and 1.4 line spacing.

However, another study contradicts these findings:

  • A study of 28 people with dyslexia, ages 14 to 38, found that:
    • Line spacing did not have a significant effect on objective readability (measured by fixation duration), subjective readability, or subjective comprehensibility.
    • Smaller line spacing (.8 compared to 1.8 line spacing) increased comprehension scores.
    • Rello, Pileot, Marcos, & Carlini, 2013

Large line spacing may not be beneficial for the general population:

  • A study of 104 people ages 14 to 54 (disability status not specified) found no effect of line spacing on readability, as measured by fixation duration.

See other sources at Raising the Floor.

Related Guidelines 

The features of the CISL tools are related to existing guidelines and best practices, including the Web Content Accessibility Guidelines (WCAG) and the Universal Design for Learning (UDL) Guidelines. The feature of adjustable line spacing is connected to:

Web Content Accessibility Guidelines(WCAG) 

  • WCAG has two levels of compliance criteria for line spacing.  To meet level AA, you just need to design your content to still be usable if the user configures their system to increase the spacing to line-and-a-half (WCAG 2.1 AA Criterion 1.4.12).  But to meet level AAA, you have to provide a way for users to increase the spacing (WCAG 2.1 AAA Criterion 14.8).

Universal Design for Learning (UDL) 

Adjustable Line Spacing in other work

Want to see what other projects are doing with Adjustable Line Spacing? See what Raising the Floor has compiled on their adjust text font, including size and spacing page.

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