Readability Checker

Flesch Reading Ease, FK Grade Level & Gunning Fog — instantly

Real-time | 100% client-side
Your Text
Reading Ease
0 Hard 100 Easy
FK Grade
Readable by a  
Gunning Fog
≤8 = easy to read  

Text Statistics

Words
Sentences
Syllables
Avg Words/Sentence
Avg Syllables/Word
Complex Words

Suggestions to Improve Readability

Paste or type your text above to see readability scores and statistics

Time Estimates

  • Reading time —
  • Speaking time —
  • Reading speed 200 wpm
  • Speaking speed 130 wpm

Flesch Score Guide

  • 90–100 Very Easy
  • 80–89 Easy
  • 70–79 Fairly Easy
  • 60–69 Standard
  • 50–59 Fairly Difficult
  • 30–49 Difficult
  • 0–29 Very Difficult

Quick Tips

  • Aim for sentences under 20 words
  • Keep words to 2 syllables or fewer
  • Target grade 6–8 for web content
  • Use active voice to reduce length

100% Private

All analysis happens locally in your browser. Your text is never sent to any server or stored anywhere.

What is Readability?

Understanding the science behind how easy your text is to read

Readability measures how easy a piece of text is to understand. It takes into account factors like sentence length, word length, and the use of complex vocabulary. Readability formulas produce a score that indicates the level of education a reader needs to comfortably understand your content.

High readability does not mean "dumbed down" — it means your ideas are communicated clearly and efficiently. Even complex topics can be explained at a grade 8 level. The world's most respected science communicators and journalists aim for simple, clear language while discussing sophisticated subjects.

Flesch Reading Ease

Scores text from 0 (very hard) to 100 (very easy). Uses average sentence length and average syllables per word. Widely used for consumer-facing documents and web content.

Flesch-Kincaid Grade

Maps text to a US school grade level. A score of 8 means the text is readable by an 8th grader. The US DoD requires most documents to score below grade 9.

Gunning Fog Index

Estimates the years of formal education required to understand the text on a first reading. Penalises long sentences and polysyllabic (3+ syllable) words heavily.

How to Use This Tool

Check and improve your content's readability in four simple steps

  1. 1
    Paste your text

    Paste a blog post, essay, landing page, email, or any content into the text area. Results update instantly as you type.

  2. 2
    Read your scores

    Check the Flesch Reading Ease badge, FK Grade Level, and Gunning Fog Index. Compare them against the reference guide on the right.

  3. 3
    Review the suggestions

    If your text scores above grade 10 or has a high average syllable count, the tool will surface specific, actionable tips to improve clarity.

  4. 4
    Edit and recheck

    Shorten long sentences, replace complex words, and paste the revised text back in to see your scores improve in real time.

Use Cases

Who benefits from checking readability?

Bloggers & Content Writers

Ensure blog posts hit the sweet spot for your audience. General readers expect grade 6–8. Aim for a Flesch score above 60 to maximise engagement and reduce bounce rate.

Copywriters & Marketers

Landing page copy must be understood instantly. Clear, concise sentences drive conversions. Use this tool to verify your copy is accessible to your widest possible audience.

Students & Academics

Check essays and papers to ensure they meet assignment readability requirements, or to calibrate your writing style before submitting to a journal with specific audience expectations.

SEO Professionals

Google favours content that satisfies user intent clearly. Readable content earns lower bounce rates, higher dwell time, and better rankings. Use readability as part of your on-page SEO checklist.

Frequently Asked Questions

Common questions about readability scores and formulas

The Flesch Reading Ease score ranges from 0 to 100. Higher scores mean the text is easier to read. A score of 60–70 is considered standard plain English. Scores below 30 are very difficult (typical of academic and legal writing). Scores above 80 are very easy (children's books and simple instructions). The formula is: 206.835 − 1.015 × (words/sentences) − 84.6 × (syllables/words).
For general web content and blogs, aim for grade 6–8. This means the text is readable by a typical middle-school student — accessible to the broadest adult audience. For technical documentation or B2B writing, grade 10–12 is acceptable. Legal and academic texts often score 16+ (college graduate level), which limits their audience significantly.
The Gunning Fog Index estimates the years of formal education a reader needs to understand your text on the first reading. It is calculated as: 0.4 × ((words/sentences) + 100 × (complexWords/words)), where complex words have 3 or more syllables. A score of 8 or below is considered easy to read. Most popular newspapers target a Fog Index of 10–12.
Reading time is estimated at 200 words per minute, which is the widely accepted average silent reading speed for adults. A 1,000-word article therefore takes approximately 5 minutes to read. Speaking time uses 130 words per minute, the average pace for presentations and public speaking. Both estimates are displayed as hours and minutes for longer texts.
The most impactful changes are: (1) Shorten your sentences — aim for under 20 words each. (2) Choose simpler words — replace polysyllabic jargon with everyday alternatives. (3) Use active voice — passive constructions add words and complexity. (4) Break up paragraphs — short paragraphs feel less intimidating and are easier to scan online.