Readability checker: Flesch score & grade level

This tool reports four established readability formulas. They agree most of the time but measure slightly different things, so seeing all four gives you a fuller picture:

• Flesch Reading Ease - a 0-100 score (higher = easier) based on average sentence length and syllables per word. The headline number for web copy.
• Flesch-Kincaid Grade Level - translates the same inputs into a US school grade, so "8.0" means an eighth-grader could read it.
• SMOG Index - estimates the years of education needed, weighted toward complex (3+ syllable) words. Widely used for health and compliance content.
• Gunning Fog - another grade-level estimate that also penalizes long sentences and complex words; a fog index under 12 is broadly accessible.

All of them boil down to two truths: shorter sentences and shorter words are easier to read. You don't need to chase a perfect score on every formula - use Flesch Reading Ease as your primary gauge and the others as a sanity check.

Readability isn't a direct Google ranking factor, but it shapes the behavioral signals that are. Hard-to-read pages get skimmed and abandoned; easy-to-read pages hold attention, earn longer dwell time, lower bounce, and deeper scroll - all signals that correlate with better rankings over time. More directly, clarity converts: when a visitor instantly understands your value and your call to action, they're far more likely to act. The average adult reads comfortably at about an 8th-grade level, and even expert audiences prefer clear writing - they're busy, often on mobile, and rarely reading word for word.

Clear writing has a new payoff: it makes your content easier for AI engines to quote. When ChatGPT, Perplexity, or Google AI Overviews assemble an answer, they favor passages that are self-contained, plainly worded, and unambiguous. Convoluted sentences with multiple clauses are harder to extract cleanly, so they're less likely to be cited. Leading with a direct answer, defining terms, and keeping sentences short doesn't just help human readers - it improves your odds of being the source an AI engine pulls from.

• Content marketers and bloggers tightening posts before publishing.
• Landing-page and CRO teams making sure the value prop reads instantly.
• Product and UX writers keeping microcopy and docs clear.
• Healthcare, finance, and legal teams who must communicate complex topics to a general audience.