Free Readability Scorer

01 · Definition

What is readability scorer?

A readability checker analyses text across multiple formulas — Flesch Reading Ease, Flesch-Kincaid Grade Level, SMOG Index and others — and returns a set of scores indicating how easy or difficult the text is to read. Each formula weights different signals: sentence length, word length, syllable count and vocabulary complexity. The median grade level combines them into a single robust summary.

This readability score tool accepts any body of text and returns all key metrics plus an estimated reading time. Paste email copy, a landing page section or a newsletter body to get an instant score. Read the in-depth readability scorer guide for target score ranges by audience type and a step-by-step rewrite checklist.

02 · Process

How it works

1. 1Paste your text.Paste any body of text — at least a full paragraph for meaningful scores. Short fragments produce unreliable results because formulas rely on sentence-count averages.
2. 2Run seven readability formulas.The tool calculates Flesch Reading Ease, Flesch-Kincaid Grade Level, SMOG Index, Coleman-Liau Index, Automated Readability Index, Linsear Write Formula and RIX in a single pass.
3. 3Read the median grade.The median grade level is the single best summary — it averages across all formulas to reduce the influence of any one metric's quirks for a specific text type.
4. 4Revise and re-run.Shorten sentences, replace long words with shorter ones, and recheck until the scores match your target audience's reading level.

03 · Risk

Why it matters

Email marketing copy written above a Grade 8 reading level consistently underperforms copy written at Grade 6–7. Not because recipients cannot understand it, but because higher-complexity text requires more cognitive effort to scan — and most people decide within a few seconds whether to read or delete. Simpler writing lowers the barrier to engagement.

Readability also affects how email copy performs through spam filters. Both very complex and unusually simple text can contribute to higher spam scores — spam filters look at vocabulary and sentence patterns as one of many signals. Hitting the right reading level range helps on both dimensions.

04 · Use cases

Common ways to use this tool

• Email copy audit. Check email body copy before sending to confirm it reads at the right level for your audience — typically Grade 6–8 for most marketing sends.
• Landing page optimisation. Score landing page copy to confirm it matches the reading level of your target segment, particularly for financial services or technical products where clarity drives conversion.
• Newsletter section review. Score each newsletter section separately to catch sections that are significantly harder to read than the rest, then simplify before sending.
• A/B copy comparison. Score two variants of the same email section to see which reads more easily — the more readable version is usually the better starting point for the test.
• Template readability standard. Set a target Flesch Reading Ease score (e.g. 60+ for mass-market sends) and use the tool as a gate before any campaign template is approved.

05 · Interpretation

What to check in the result

• Flesch Reading Ease below 60. This text is in "Fairly Difficult" territory or worse. Shorten sentences, replace multi-syllable words with simpler alternatives, and recheck.
• Median grade above 10. Most email copy should target Grade 7–9. Grade 10+ means the text reads like academic or legal writing — simplify unless your audience specifically expects that register.
• SMOG Index above 12. SMOG specifically measures polysyllabic word load. Above 12 means you are using many long words — simplify vocabulary regardless of how short your sentences are.
• Reading time above 90 seconds. Marketing emails read in under 90 seconds outperform longer ones. Cut sections, tighten paragraphs or split into a series if reading time is significantly over that threshold.
• Large gap between Flesch and grade scores. If Flesch Reading Ease looks acceptable but grade levels are high (or vice versa), your text has an unusual sentence-length-to-word-complexity mix. Review both dimensions separately to diagnose the issue.