Readability Checker

Paste any text to get five readability scores instantly: Flesch-Kincaid, SMOG, Gunning Fog, Automated Readability Index, and Coleman-Liau. Target Grade 8-10 for most web content.

Free forever. No signup. All calculations run in your browser.

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Scores

Paste text on the left and click Check Readability to see your scores.

How It Works

Five indexes, one text input

Flesch-Kincaid Grade Level

0.39 x (words/sentences) + 11.8 x (syllables/words) - 15.59

SMOG Index

3 + sqrt(complex words x 30/sentences). Complex = 3+ syllables.

Gunning Fog Index

0.4 x (words/sentences + 100 x complex words/words)

Automated Readability Index

4.71 x (chars/words) + 0.5 x (words/sentences) - 21.43

Coleman-Liau Index

0.0588 x L - 0.296 x S - 15.8. L = letters/100 words, S = sentences/100 words.

Need Content That Ranks?

Readability is one signal. We optimize all of them.

Well-written content that misses keyword placement, topical depth, internal linking, and schema markup still does not rank. Our content service combines readability with every on-page signal that matters.