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Email readability scorer

Paste your email text and instantly get a Flesch-Kincaid readability score, jargon flags, passive voice detection, and specific suggestions to make your writing clearer.

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Your results

Paste an email and hit analyze to check its readability.

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readability grade
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Flesch-Kincaid score
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avg sentence length
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passive voice
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jargon words
Readability
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Your email with issues highlighted
Jargon Passive voice
Jargon flags & simpler alternatives
Paragraph length analysis
Rewrite suggestions

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Email readability: what you need to know

What is Flesch-Kincaid readability?

The Flesch-Kincaid readability score measures how easy a text is to read based on sentence length and syllable count. Scores range from 0 to 100, where higher scores mean easier reading. A score of 60-70 is considered plain English that most adults can read comfortably. The formula was originally developed for the US Navy to assess the readability of technical manuals and has since become the standard readability metric used in education, publishing, and business writing.

What's a good readability score for emails?

For most business emails, aim for a Flesch-Kincaid score of 60-80. Emails to executives should score even higher (70-90) since busy leaders prefer short, clear sentences. Technical emails to peers can be slightly lower (50-70) since the audience understands domain terminology. Client-facing emails should target 65-85 to ensure clarity across different reading levels. The best-performing sales and marketing emails tend to score 70 or above.

How does audience affect readability requirements?

Different audiences have different readability needs. Executives want concise, scannable emails with short sentences and no jargon. Technical teams can handle more complex language and domain-specific terms. Client communications should be clear and free of internal jargon. General audiences need the simplest language possible. Matching your writing to your audience improves comprehension and response rates significantly.

Does readability affect email deliverability?

Indirectly, yes. While spam filters do not directly measure Flesch-Kincaid scores, poorly written emails with excessive jargon, long sentences, and complex language tend to have lower engagement rates. Low engagement (fewer opens, clicks, and replies) signals to email providers that your messages are unwanted, which can hurt your sender reputation and deliverability over time. Clear, readable emails get more replies.

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