A cognitive bias described by Daniel Kahneman in which people judge an experience primarily by how they felt at its most intense moment and at its conclusion — not by the average across all moments. Designers use this principle to create emotionally positive peaks at key interactions and satisfying, memorable endings to product flows.
Common contexts
- Designing a celebratory animation for the moment a user completes their first successful export in a data tool
- Mapping a checkout journey to identify the most emotionally charged moment — payment confirmation — and investing in its microcopy and visual design
- Crafting a warm, reassuring final screen for a health app's anxiety check-in flow to counteract the stress of the questions
Use when
Apply the peak-end rule when designing flows where emotional memory matters — onboarding completions, purchase confirmations, successful first-use moments, and any flow that ends a significant user effort.
Avoid when
Avoid investing heavily in peak-end moments when the functional baseline is broken — a beautiful success screen doesn't recover trust after a painful checkout process; fix the pain points before designing the peak.
Users don't remember your whole product — they remember the moment they first succeeded and the last thing that frustrated them, so one unresolved exit state can permanently colour weeks of otherwise good experience.
Real-world examples
- Chewy's pet loss condolence cards — sent unsolicited when a customer's pet passes away — are a deliberate peak-end rule strategy: the emotional high of unexpected kindness at a sensitive moment generates 30%+ referral rates.
- Disney parks place gift shops at the exit of every major ride — positioning a positive purchasing opportunity at the natural 'end' of the experience to shape guests' lasting memory of the attraction.
- Airbnb's post-stay review prompt appears 24 hours after checkout (not immediately), timed to capture the memory of the experience after the friction of packing has faded but while positive moments remain salient.