Flesch-Kincaid Readability Calculator
Flesch Reading Ease 0 —
Flesch-Kincaid Grade Level 0 —
Very difficult Standard Very easy
0 sentences 0 words 0 syllables
Paste any text and get the Flesch Reading Ease and Flesch-Kincaid Grade Level scores instantly — no button, no signup, no wait even on long documents.
How it works
- Paste your text into the box
- Both scores update live, with a plain-language difficulty label
- Sentence, word, and syllable counts are shown underneath for context
Frequently asked questions
How do I interpret the Flesch Reading Ease score?
It's a 0–100 scale where higher means easier to read. 90+ is very easy (5th grade level), while below 30 is very difficult (college graduate level).
Why does this work best on English text?
Syllable counting uses an English vowel-pattern heuristic, so accuracy drops for other languages — the Flesch-Kincaid formula itself was designed for English.
Does it slow down on longer documents?
No — the counting logic is lightweight pure JavaScript with a short debounce, so even long articles update without a noticeable delay.
Related tools
From the blog
Update history
- 2026-09-09 Added: a color-coded gauge showing where your score falls on the very-difficult-to-very-easy scale, plus a downloadable for-fun certificate (PNG, with QR code) of your readability result.
- 2026-08-30 Added: a cover image — used as the card thumbnail, social share image, and blog title image.
- 2026-08-29 Launched: live Flesch Reading Ease + Flesch-Kincaid Grade Level scoring with debounced instant recalculation, no button, no signup.