Free Readability Checker

A readability checker analyzes your text using established scoring algorithms — primarily Flesch-Kincaid — to measure how easy or difficult it is to read. It calculates a grade level (the U.S. school grade needed to understand the text) and a reading ease score (0–100, where higher means easier to read).

These scores are derived from concrete metrics: average sentence length, average syllables per word, and total word count. Longer sentences and polysyllabic words push scores toward “difficult,” while shorter sentences with common vocabulary score as “easy.” The math is deterministic — the same text always produces the same score.

Readability analysis matters because most online content performs best at a 6th–8th grade reading level. Academic papers, legal documents, and technical writing naturally score higher, but knowing your score helps you calibrate for your specific audience.

Anyone writing for an audience benefits from knowing their text's readability score — but some use cases are especially high-impact.

Writers consistently overestimate the readability of their own text. You understand what you wrote, so it feels clear — but your reader doesn't have your context. Flesch-Kincaid provides an objective, formula-based measurement that removes guesswork.

The scoring formulas have been validated across decades of educational research. They're used by the U.S. military for technical manuals, by healthcare organizations for patient materials, and by newsrooms to calibrate article complexity. They work because sentence length and syllable count are reliable proxies for cognitive load.

This tool runs the calculations in your browser with zero latency. No API calls, no server processing, no word limits. Paste a 10,000-word document and get instant scores — then edit and watch them update in real time. That feedback loop is what makes readability checking useful: not a one-time report, but a live guide while you write.