Readability Scorer
Paste your text — get six readability scores, a grade level, reading time, and a marked-up copy showing the long sentences, passive voice and adverbs that drag it down.
How to Use Readability Scorer in 3 Steps
Paste the text
Drop in anything from a tweet to a report — plain text, Markdown or HTML (tags are stripped). Scores update as you type.
Read the scores
Flesch Reading Ease runs 0–100 (higher is easier; 60–70 is plain English, newspapers sit around 50–60). The grade-level scores (Flesch-Kincaid, Gunning Fog, SMOG, Coleman-Liau, ARI) estimate the US school grade needed; the consensus is their median. Aim for grade 8 or below for a general audience.
Fix what is highlighted
Long sentences, possible passive voice and -ly adverbs are marked in the text. Split long sentences, turn “was approved by the board” into “the board approved”, and cut adverbs that add nothing. Re-check the numbers as you edit.
Readability Scorer — Frequently Asked Questions
How are the scores calculated?
Standard formulas on word, sentence and syllable counts: Flesch Reading Ease = 206.835 − 1.015 × (words ÷ sentences) − 84.6 × (syllables ÷ words); Flesch-Kincaid = 0.39 × (words ÷ sentences) + 11.8 × (syllables ÷ words) − 15.59; Gunning Fog = 0.4 × ((words ÷ sentences) + 100 × (complex words ÷ words)); SMOG = 1.043 × √(polysyllables × 30 ÷ sentences) + 3.1291; Coleman-Liau and ARI use letters per word and words per sentence. Syllables come from an English vowel-group heuristic, so expect ±1 on unusual words.
Which languages does it work for?
The formulas and the syllable counter are calibrated for English. Other Latin-script languages produce numbers, but they are not meaningful — German compounds and French silent endings break the assumptions.
What counts as a “complex” word?
Three or more syllables, as in the Gunning Fog and SMOG definitions. Proper nouns and compound words are not excluded, so technical text scores slightly harder than a human rater would say.
How accurate is the passive-voice detection?
It is a heuristic: a form of “to be” followed by a past participle (“was approved”, “is being reviewed”). It catches most cases and also flags some adjectives (“was tired”) — treat each highlight as a prompt to look, not a verdict. Turn it off in Settings if it gets in the way.
How is reading time estimated?
Words divided by your chosen speed (200 words per minute is a typical adult silent-reading rate); speaking time uses 130 wpm. Short texts round up to one minute.
Is my text uploaded anywhere?
No. Everything runs in JavaScript inside your browser tab. Your text and files are never sent to Toolity or anyone else.