TextCheck

Readability checker

Get six readability scores at once, an average grade level, and the sentences that make your text hardest to read.

Average grade level

–

Paste at least a few sentences.

  • Words0
  • Sentences0
  • Syllables / word0.00
  • Words / sentence0.0
  • Complex words (3+ syllables)0%
Readability scores
FormulaScoreMeaning
Scores appear here as soon as you type.

What actually moves a readability score

Most formulas use just two ingredients: sentence length and word length. Drag them and watch.

Reading Ease

60

Fairly difficult

Flesch–Kincaid grade

9.9

Grade 10

Where the 206.8 points go

sentence length −20.3word length −126.9

Notice the word-length slider moves the score far more: one extra syllable per word costs 84.6 points, while one extra word per sentence costs just over 1. Swapping “utilise” for “use” matters more than you’d think.

The six formulas

FormulaMeasuresBest for
Flesch Reading Ease0–100 ease score from words per sentence and syllables per wordGeneral writing, web copy
Flesch–Kincaid GradeUS school grade from the same inputsEducation, US government documents
Gunning FogGrade from sentence length and share of 3+ syllable wordsBusiness writing
SMOGGrade from 3+ syllable words per 30 sentencesHealth and patient information
Coleman–LiauGrade from letters per word and sentences per 100 wordsChecks that don’t rely on syllable counting
Automated Readability IndexGrade from characters per word and words per sentenceTechnical manuals

What is a good readability score?

For content aimed at the general public, aim for a Flesch Reading Ease of 60 or more and a grade level of 8 or below. The average US adult reads comfortably at about an 8th-grade level, and health organisations such as the NIH recommend patient materials at grade 6–8. Academic and legal writing will naturally score harder.

What readability formulas can’t tell you

Formulas count; they don’t read. A short sentence of nonsense scores as “easy”, and a well-structured technical explanation can score as “hard”. Use the score to spot problem areas, then judge with your own eyes, or ask a reader from your audience.

Questions people ask

Why do the formulas give different grades?

Each uses different inputs (syllables, letters, or complex words) and was calibrated on different reading material. Looking at the average, and at trends as you edit, is more useful than any single number.

How much text do I need?

At least 100 words gives a stable result. SMOG was designed for samples of 30 sentences.

How are syllables counted?

With a rule-based estimate of vowel groups, adjusted for silent e, -ed and -es endings and common patterns. It matches dictionary counts for the large majority of English words.

Is my text stored?

No. Scores are calculated in your browser.

More free writing tools

Flesch Reading EasePlus Flesch–Kincaid grade levelGunning Fog IndexYears of schooling neededSMOG IndexThe health-writing standardGrammar checkerSpelling, grammar, punctuation and style in one passSpell checkerUS or UK dictionary, with your own word listPunctuation & comma checkerComma splices, spacing, missing commasSentence checkerEvery sentence graded, with AI fixesPassive voice checkerFind “was done by” and flip it to activeRun-on sentence checkerFused sentences and comma splices