Text Readability Checker

The Flesch-Kincaid readability tests are two formulas developed by Rudolf Flesch and J. Peter Kincaid. The Flesch Reading Ease score ranges from 0 to 100, where higher scores indicate easier text. A score of 60–70 is generally ideal for consumer-facing content. The Flesch-Kincaid Grade Level translates the same data into a US school grade equivalent — e.g., a score of 8 means the text is readable by an average 8th grader.

It depends on your audience. The US average adult reads at a Grade 7–8 level. Leading style guides recommend Grade 6–8 for general web content, news articles, and marketing copy. Academic papers and legal documents typically sit at Grade 14–18. For accessibility and inclusivity — especially for users with dyslexia, ADHD, or English as a second language — aim for Grade 6–8 or lower wherever possible.

Words with 3 or more syllables are highlighted as "complex words." These are the primary driver of difficult readability scores in both the Gunning Fog and SMOG formulas. By identifying complex words visually, you can decide whether to replace them with simpler alternatives, add definitions, or restructure your sentences.

The SMOG (Simple Measure of Gobbledygook) Index was designed to work reliably only on texts of 30 sentences or more. Its polysyllable-counting formula produces unreliable results on shorter samples. For short texts, the other four formulas — particularly Flesch-Kincaid and Coleman-Liau — provide more reliable scores.

No. All five readability formulas used here were developed and validated for English-language text. Applying them to other languages will produce inaccurate results, because syllable counts, sentence structure, and word length patterns differ significantly across languages. For best results, use English text only.