A readability formula scores how hard a text is to read from two measurable properties — how long its sentences are, and how complex its words are, counted as syllables per word for Flesch and Flesch–Kincaid and as the share of three-or-more-syllable words for Gunning Fog and SMOG. Paste your text to grade how easy it is to read — Flesch Reading Ease, Flesch–Kincaid grade level, Gunning Fog and SMOG update live as you type. Clearer copy helps both readers and AI answer engines. Everything runs in your browser.
Flesch Reading Ease
— —Flesch–Kincaid Grade
—
Gunning Fog
—
SMOG Index
—
Reading Time
—
Words
—
Sentences
—
Syllables
—
Avg words / sentence
—
Avg syllables / word
—
Complex words
—
A complex word is any word of 3 or more syllables, and reading time assumes 200 words per minute. Syllable counts are a heuristic estimate, so the scores are approximate. The formulas are the standard published ones.
Paste or type your text into the box — a paragraph, a blog draft, a product description — and the scores update as you write. The headline number is Flesch Reading Ease on a 0–100 scale, where higher means easier; its plain-English band tells you roughly which reading level the text sits at. Alongside it you get Flesch–Kincaid grade level, the Gunning Fog and SMOG indices, and the raw counts — words, sentences, syllables, averages and estimated reading time — that the formulas are built from.
Readability is a signal, not a rule: aim for plainer prose where your audience is broad, and accept denser text where readers are specialists. Because syllables are estimated rather than looked up in a dictionary, treat the numbers as close approximations. Nothing you paste is uploaded — it all runs locally in your browser.
Once the prose reads cleanly, check which terms it actually leans on with the keyword density checker, tidy the URL with the slug generator, and see how the finished page will look in results with the SERP snippet preview.
Flesch Reading Ease runs from 0 to 100 and a higher score means easier text. These are the seven bands this checker uses — the label in the “Band shown” column is exactly what appears under your score.
| Flesch score | Band shown | Grade level | Reads like |
|---|---|---|---|
| 90–100 | Very easy | 5th grade | Very short sentences and everyday words |
| 80–89 | Easy | 6th grade | Conversational English, as in popular fiction |
| 70–79 | Fairly easy | 7th grade | Light, plain writing that suits a wide audience |
| 60–69 | Plain English | 8th–9th grade | Plain English — the usual target for web and news copy |
| 50–59 | Fairly difficult | 10th–12th grade | Denser prose, comfortable for informed readers |
| 30–49 | Difficult | College | Long sentences and specialist vocabulary — academic or trade writing |
| 0–29 | Very confusing | College graduate | Best understood by graduates already familiar with the subject |
For a general audience, aim for a score of 60–70 — the plain-English band, roughly an 8th- to 9th-grade reading level. Technical and academic writing sits lower by nature, so treat the band as a target rather than a pass mark. The checker labels any score of 90 or above as very easy, and the formula can return a value slightly outside 0–100 on unusual text.