Readability Checker

THE SMALL PRINT, MADE CLEAR.

A reading level checker.
Not a verdict on your writing.

A readability score estimates how demanding your sentence and word lengths are. Use this readability test to compare drafts, then read the text yourself for meaning and tone.

What is supported?

English prose, one document at a time. Paste or import TXT, Markdown, HTML, DOCX and text-based PDF. Scanned PDFs need OCR elsewhere. Legacy DOC is not supported: save as DOCX or paste the text. PDF reading order may need correction.

The limit is 100,000 characters, a 10 MB file and 100 PDF pages. No daily quota. Files are read on your device. A URL request goes directly to that website and works only if it permits browser access; your draft is never sent.

How are the scores calculated?

W = words; S = sentences; Y = estimated syllables; C = letters and digits; L = letters per 100 words; P = sentences per 100 words. Words include contractions; sentence boundaries use the browser’s English sentence segmenter. Syllables use the open-source syllable estimator. Names and unfamiliar words may be miscounted.

• Flesch Reading Ease: 206.835 − 1.015(W/S) − 84.6(Y/W).
• Flesch–Kincaid Grade: 0.39(W/S) + 11.8(Y/W) − 15.59.
• ARI: 4.71(C/W) + 0.5(W/S) − 21.43.
• Coleman–Liau: 0.0588L − 0.296P − 15.8.
• SMOG: 1.043√(polysyllables × 30/S) + 3.1291. Shown only with at least 30 sentences.
• Gunning Fog estimate: 0.4 × (W/S + 100 × polysyllables/W). This simplified count includes names and inflections.
• Linsear Write: first 100 words, one point for a word under three syllables and three otherwise; points/sentences, then divide by two (subtract two first if the value is at most 20).
• FORCAST: first 150 words; 20 − (single-syllable words/10).

Scores are rounded only for display, never forced into a 0–100 range. Negative grades are shown as “Below grade 1”. No invented overall score or reading-age conversion. Formula references: Textstat documentation and source. A formula is an estimate, not a validation of understanding.