Jakob's Law: Why Familiarity Beats Innovation in UX
Jakob's Law states users spend most of their time on other sites, so they expect yours to work the same way. Learn when to follow conventions and when breaking them is worth the risk.
What Is Jakob's Law?
Coined by Jakob Nielsen of the Nielsen Norman Group, Jakob's Law states: "Users spend most of their time on other sites. This means that users prefer your site to work the same way as all the other sites they already know." Users arrive with a mental model — a compressed, pre-existing understanding of how websites and apps work — built from thousands of prior interactions. Every time your interface deviates from that model without a clear payoff, you tax their attention.
"Users spend most of their time on other sites. This means that users prefer your site to work the same way as all the other sites they already know."— Jakob Nielsen / Laws of UX
Mental Models and Convention
A mental model is a user's internal representation of how a system works. They expect: logo top-left links to home; shopping cart top-right; search in the header; hamburger menu on mobile. These aren't arbitrary — they're conventions that emerged because they worked and then became self-reinforcing through widespread adoption.
When to Follow Convention
- Navigation placement and iconography (back arrow, search magnifier, home icon).
- Form structure and validation patterns.
- Link colour and underline (blue, underlined remains the most universally recognised).
- Checkout flows — Amazon and Stripe have conditioned hundreds of millions of users.
- Error and success feedback patterns.
When to Break Convention
Innovation is warranted when: the existing convention doesn't serve your specific user's context; your product operates in a domain with no established conventions; or the UX gain is large enough to justify the learning cost. The key test: can new users figure it out within seconds, without instruction?
Key Takeaways
- Users bring existing mental models — leverage them rather than fight them.
- Convention reduces learnability cost; deviation increases it.
- Innovation earns its place when it solves a real problem conventions cannot.
- User test any non-conventional pattern before shipping — your clever idea may be their confusing obstacle.
