How this readability test works
Paste a draft and the checker splits it into sentences and words, counts syllables and letters, and feeds those counts into seven published formulas. Each one looks at your text slightly differently:
- Flesch Reading Ease and Flesch-Kincaid Grade Level weigh sentence length and syllables per word.
- Gunning Fog and SMOG count words of three or more syllables.
- Coleman-Liau and the Automated Readability Index count letters instead of syllables.
- Dale-Chall checks each word against a list of about 3,000 words familiar to fourth-graders.
The eye chart averages the six grade-level results into one reading grade. That average is steadier than any single formula, because each formula’s blind spot is different.
What to do with the highlights
Start with the brightest highlighted sentences. A sentence that scores grade 14 on its own is usually doing two jobs; splitting it at the “and”, “which” or “because” fixes most of them. Then look at passive voice. “The report was approved by the board” becomes “The board approved the report”: shorter, and the reader learns who acted first.
Don’t chase a perfect number. A readability score cannot tell whether your argument is clear or whether a technical term is the right one for your audience. Use the score to find the rough patches, then read those sentences aloud.
Readability for SEO content
Search engines don’t reward a Flesch score directly, but readers do. Content that answers the question in plain words keeps people on the page, and plain words are what people type into search. Add your target keyword to check that it appears early, sits in a heading and isn’t repeated so often that it sounds forced. For a deeper phrase-by-phrase breakdown, use the keyword density checker.