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Readability Checker — Flesch–Kincaid

Flesch Reading Ease and Flesch–Kincaid grade level, with word/sentence/syllable stats. Client-side; text never leaves your device.

Free No signup Client-side Privacy friendly Updated

How to use

  1. 1 Paste your text into the box.
  2. 2 See the Flesch Reading Ease score and Flesch–Kincaid grade level.
  3. 3 Word, sentence and syllable stats help you simplify dense writing.

Why use this tool

  • Two standard readability scores plus the stats behind them.
  • Spot long sentences and complex words that hurt readability.
  • Runs entirely in your browser — your text never leaves your device.

Frequently asked questions

What is the Flesch Reading Ease score?

A 0–100 score where higher is easier. 60–70 is plain English (8th–9th grade); below 30 is very difficult (college graduate).

What is the Flesch–Kincaid grade level?

An estimate of the U.S. school grade needed to understand the text — e.g. 8.0 means an average 8th grader should follow it.

How are syllables counted?

With a vowel-group heuristic. It is accurate for most words but can miss unusual spellings, so treat the scores as estimates.

How can I improve readability?

Use shorter sentences and simpler, shorter words. Both drive the scores down toward an easier reading level.

What is Readability Checker?

A readability checker scores how easy a passage is to read using the Flesch Reading Ease and Flesch–Kincaid grade-level formulas, based on sentence length and syllable count.

Features

Flesch Reading Ease

Computes the 0–100 score from words-per-sentence and syllables-per-word.

Grade-level label

Maps the score to a reading level from 5th grade to college graduate.

100% private

Runs on your device — your text is never uploaded.

Example

Input

The quick brown fox jumps over the lazy dog.

Output

Flesch Reading Ease = 94.3 (Very easy — 5th grade)

Common use cases

  1. 1

    Simplify writing

    Check whether an article or email is easy enough for your audience.

  2. 2

    Match a grade level

    Tune content toward a target reading level for education or marketing.

  3. 3

    Compare drafts

    See which revision reads more easily.

Summary

Zerethon's readability checker scores text with the Flesch Reading Ease formula in your browser, based on average sentence length and syllables per word, and maps the score to an approximate US grade level. Everything runs client-side — nothing is uploaded.

Category
Writing
Pricing
Free
Privacy
Browser-based
Signup
Not required

References

Privacy

Your data never leaves your browser unless explicitly stated. Readability Checker runs entirely client-side — no server upload, no logging, no tracking of your input.

How-to guides

How to count words

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