Readability Checker
Check Flesch, Gunning Fog, SMOG, and five other readability scores.
What Readability Scores Measure
Readability formulas estimate how difficult a text is to read based on measurable features like sentence length and word complexity. The Flesch Reading Ease score ranges from 0 to 100 — higher scores indicate easier text. A score of 60-70 is considered standard for most audiences. The Flesch-Kincaid Grade Level converts this to a US school grade level, making it intuitive: a score of 8 means an average 8th grader could understand the text.
The Gunning Fog Index estimates the years of education needed to understand text on first reading. It counts "complex words" (three or more syllables) as a proxy for difficulty. The Automated Readability Index (ARI) uses character count per word rather than syllables, making it faster to compute and less dependent on pronunciation rules.
Why Readability Matters for SEO
Google doesn't directly use readability scores as a ranking factor, but readable content tends to have lower bounce rates, higher time-on-page, and more engagement — all of which indirectly affect rankings. Studies show that most successful web content targets a Flesch score of 60-70 (8th-9th grade level), even for professional audiences. The Plain Language Movement in government and legal writing has demonstrated that simpler writing improves comprehension and compliance.
How to Improve Readability
Use shorter sentences (aim for 15-20 words average). Choose simpler words when possible (use vs utilize, help vs facilitate). Use active voice instead of passive. Break long paragraphs into shorter ones. Use subheadings, bullet points, and white space. These changes improve readability scores and, more importantly, reader comprehension and engagement.
Target Scores by Content Type
Blog posts: Flesch 60-70. Children's content: 80-100. Academic papers: 30-50. Legal documents: 20-40. Marketing copy: 60-80. News articles: 50-60. Technical documentation: 40-60. Matching your readability to your audience ensures your message is understood as intended.
Limitations of Readability Formulas
Readability formulas measure surface features — they cannot assess logical coherence, cultural context, or domain knowledge requirements. A text using simple words in random order would score as "easy" despite being incomprehensible. Use readability scores as one input among many when evaluating text quality.