cognitive-fluency-psychology

Run the 5-second test on headlines and CTAs, then check typography, contrast, sentence length, and word choice against the fluency checklist. Rewrite jargon-heavy copy into short, concrete benefit statements and measure bounce rate and conversion changes.

Show your content to someone unfamiliar with the product for exactly five seconds, then ask what it is, who it is for, and what to do next. If they struggle to answer, the content fails the fluency test and needs simplification.

Research shows identical instructions in simple fonts are estimated to take 8 minutes versus 15+ minutes in decorative fonts. Complex typography raises perceived difficulty and lowers the likelihood users start a task.

Body text should be at least 16px with a contrast ratio of 4.5:1 or higher. Sentences should stay under 20 words, use everyday vocabulary a 12-year-old understands, and favor active voice with one idea per paragraph.

Fluency optimization matters most for high-stakes content like headlines, CTAs, pricing, and onboarding. Technical documentation for expert audiences may legitimately require domain terminology, though structure and hierarchy rules still apply.