Line Length Readability

Paste text or enter a CSS column width to instantly check whether your line lengths fall within the WCAG-recommended 45-75 characters per line range.

Tip: use real column-wrapped text for accurate results.

Paste text or use the CSS Estimator, then click Analyze.

Line Length Reference

Too short (< 45 CPL)
Choppy rhythm; uncomfortable for sustained reading.
Optimal (45-75 CPL)
Recommended by typographers and readability researchers.
Acceptable (76-80 CPL)
Within WCAG 1.4.8 AAA ceiling but above ideal.
Too long (> 80 CPL)
Fails WCAG 1.4.8 AAA; high risk of eye-tracking errors.

Summary

Paste text or enter a CSS column width to instantly check whether your line lengths fall within the WCAG-recommended 45-75 characters per line range.

How it works

  1. Paste body text into the input area — each line break counts as a separate line.
  2. The tool counts raw characters per line (including spaces) for every line.
  3. Average, minimum, maximum, and median CPL are computed and displayed.
  4. Each metric is benchmarked against the ideal range (45-75 CPL) and the WCAG 1.4.8 AAA ceiling (80 CPL).
  5. A per-line breakdown table highlights lines that are too short, optimal, or too long.
  6. Switch to the CSS estimator tab to calculate expected CPL from container width, font size, and font family.

Use cases

  • Audit body copy before publishing to confirm it meets WCAG 1.4.8 AAA line length requirements.
  • Evaluate existing web page text for typography readability issues.
  • Check article or blog post column widths against the 45-75 CPL guideline.
  • Validate e-learning course text line lengths for improved comprehension.
  • Estimate CPL for a CSS layout using container width and font size inputs.
  • Review newsletter or email templates for optimal line length.
  • Support UX writers and content designers with objective line-length data.
  • Identify unusually short or long lines that break reading rhythm.

Frequently Asked Questions

Last updated: 2026-07-01 · Reviewed by Nham Vu