---
title: "Readability & Plain Language Checker | Kindness Junction"
description: "Check how easy your writing is to read: Flesch Reading Ease, Flesch-Kincaid grade, long sentences, passive voice and plainer words, all highlighted."
url: https://kindnessjunction.sbs/readability-checker/
---

# Plain-language and readability checker

Paste a letter, notice, form or web page. See its reading ease and grade level, then fix what makes it hard: long sentences, passive voice and wordy phrases, each highlighted in your text.

## What the scores mean

**Flesch Reading Ease** is 206.835 − 1.015 × (words per sentence) − 84.6 × (syllables per word). Higher scores mean easier reading; most everyday text falls between 0 and 100. **Flesch-Kincaid Grade** is 0.39 × (words per sentence) + 11.8 × (syllables per word) − 15.59, which gives roughly the years of US schooling a reader needs. WCAG 2.2's success criterion 3.1.5 (level AAA) asks for a simpler version when text needs more than nine years of school.

Both formulas only count. They cannot tell whether your words are familiar, your order is logical or your reader will understand. Use them to compare drafts, not as a pass mark.

## How the highlights work

Syllables are estimated from vowel groups, so counts can be off by one on unusual words. Passive voice is found by a pattern: a form of *be* followed by a past participle, such as *was sent*; some adjectives slip through, and some passives are missed. The US federal plain language guidelines recommend the active voice, one idea per sentence, and paragraphs of no more than 150 words. The wordy-phrase list is ours, with plainer choices beside each.

Writing the confirmation email for an event sign-up? Sign up once yourself with a [free temporary inbox from CleanTempMail](https://cleantempmail.com/) to see the email exactly as people receive it, then paste its text here to check how plain it reads.

## Sources

- Flesch R. A new readability yardstick. *Journal of Applied Psychology* 1948;32(3):221–233. [doi:10.1037/h0057532](https://doi.org/10.1037/h0057532)
- Kincaid JP, Fishburne RP, Rogers RL, Chissom BS. *Derivation of new readability formulas for Navy enlisted personnel*. Research Branch Report 8-75, 1975. [stars.library.ucf.edu/istlibrary/56](https://stars.library.ucf.edu/istlibrary/56/)
- W3C. [Understanding Success Criterion 3.1.5: Reading Level](https://www.w3.org/WAI/WCAG22/Understanding/reading-level.html).
- Digital.gov. [Federal plain language guidelines: clear and short](https://digital.gov/guides/plain-language/writing/clear-short) and [writing](https://digital.gov/guides/plain-language/writing).

## Questions

**Is my text sent anywhere?**

No. The checks run in your browser and nothing you paste is uploaded or saved.

**What should I aim for?**

Write for your actual readers and test with them if you can. For the public, shorter sentences, common words and the active voice almost always help; the scores just show whether a draft moved in the right direction.

**Does it work for other languages?**

No. The formulas and syllable counting are for English.