Processing fluency
Things that are easy to read and take in tend to be liked more, and choices between them feel easier to make.
Four of the eight page areas.
It also applies sitewide, on every page. See everything at work on every page
Five ways to use it, and one to avoid.
- Set legible type at a comfortable size.
- Give text a contrast of at least 4.5:1.
- Write copy in plain language.
- Use clean layouts and clear product names.
- Keep prices, options and comparison tables easy to read.
- Avoid: using ease of reading to dress up misleading claims.
Effects on liking are well documented but often small. Shop field evidence is thin.
A hard-to-read font made people more likely to put off choosing.
In lab studies, Novemsky and colleagues found a hard-to-read font made people more likely to put off choosing. A 2025 replication found text contrast did not change how true statements seemed. Effects on liking are well documented but often small, and shop field evidence is thin. A registered report by Landwehr and Eckmann found fluency also amplified existing reactions, so it can make a disliked thing seem worse.
Five sources, each checked.
Last reviewed
WCAG 2.2 level AA requires a text contrast ratio of at least 4.5:1 (3:1 for large text), and the European Accessibility Act has covered ecommerce services for EU consumers since 28 June 2025, with an exemption for microenterprises. Ease of reading can make a claim feel more convincing whether or not it is true, so it must not be used to dress up misleading claims.
This is simply a pointer to check, not legal advice. Seek legal advice before you put this principle into action.