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.
Estimate characters per line from layout parameters.
Paste text or use the CSS Estimator, then click Analyze.
CSS Estimate Result
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characters per line (estimated)
Based on the average character width ratio for the selected font family. Actual CPL may vary by typeface.
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Avg CPL
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Median CPL
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Min CPL
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Max CPL
Compliance Check
Per-Line Breakdown
| # | CPL | Status | Line preview |
|---|
Line Length Reference
Too short (< 45 CPL)
Choppy rhythm; uncomfortable for sustained reading.
Choppy rhythm; uncomfortable for sustained reading.
Optimal (45-75 CPL)
Recommended by typographers and readability researchers.
Recommended by typographers and readability researchers.
Acceptable (76-80 CPL)
Within WCAG 1.4.8 AAA ceiling but above ideal.
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.
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
- Paste body text into the input area — each line break counts as a separate line.
- The tool counts raw characters per line (including spaces) for every line.
- Average, minimum, maximum, and median CPL are computed and displayed.
- Each metric is benchmarked against the ideal range (45-75 CPL) and the WCAG 1.4.8 AAA ceiling (80 CPL).
- A per-line breakdown table highlights lines that are too short, optimal, or too long.
- 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
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Last updated: 2026-05-29 ·
Reviewed by Nham Vu