Readability Checker — Flesch Score, Grade Level & Fog Index

Free readability checker with Flesch Reading Ease, Flesch-Kincaid Grade Level and Gunning Fog Index. Analyse any text and get a colour-coded score.

Paste any text to instantly get Flesch Reading Ease, Flesch-Kincaid Grade Level and Gunning Fog Index scores with colour-coded results. See average sentence length and syllables per word to understand exactly what is making your text harder or easier to read.

When to Use the Readability Checker

Use when writing blog posts, marketing copy, educational materials, legal documents or any content where readability affects engagement and comprehension.

Tips

  • Aim for a Flesch Reading Ease score above 60 for web content — this matches the reading level of most adults.
  • Break long sentences into shorter ones to quickly improve all three readability scores.
  • Replace multi-syllable words with simpler alternatives to lower your grade level.
  • Check readability before publishing any content that targets a general audience.

Frequently Asked Questions

What is the Flesch Reading Ease score? ▾

The Flesch Reading Ease score rates text on a scale of 0 to 100. Higher scores mean easier to read. A score of 60-70 is considered ideal for general audiences, matching plain English that most adults can understand.

What is the Flesch-Kincaid Grade Level? ▾

The Flesch-Kincaid Grade Level converts readability into a US school grade. A score of 8.0 means an average eighth grader can understand the text. Most web content should target grade 6-8.

What is the Gunning Fog Index? ▾

The Gunning Fog Index estimates the years of formal education needed to understand text on a first reading. A score of 12 or above requires college-level reading ability.

What is a good readability score? ▾

For web content, aim for a Flesch Reading Ease of 60+ and a grade level of 6-8. Journalism typically targets grade 8-10, while academic writing often scores grade 12+.

How are syllables counted? ▾

The tool uses a rule-based English syllable counting algorithm that handles common patterns like silent-e, vowel groups and common suffixes. It is accurate for standard English text.

Does my text get sent anywhere? ▾

No. All analysis runs entirely in your browser using JavaScript. Your text is never transmitted to any server.

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