John Lewis basket optimisation
Boosting conversion and revenue through targeted UX improvements to the online basket experience.
Quick overview
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Role: Lead UX Designer
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Company: John Lewis
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Timeline: 2019
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Tools: Sketch, Axure, SessionCam, Adobe Analytics
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Impact:
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£1.8m/year benefit from improved error messaging
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£6.6m/year benefit from improved visibility of 'Continue to checkout' CTA on mobile
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Total projected benefit: £8.4m annually through conversion optimisation
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Situation
The basket page on JohnLewis.com had not been actively maintained for several years. Existing research showed that optimising basket performance by just one basis point could deliver £14M in annual revenue, making it a high-impact opportunity.
Task
As part of a new, cross-functional team, I was tasked with:
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Identifying key UX pain points
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Migrating the basket to React from a legacy monolithic platform
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Designing improvements to increase conversion and support accessibility
Action
As Lead UX Designer, I:
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Audited the experience using SessionCam, analytics, and usability testing
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Consolidated prior research and A/B test results to uncover insights
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Conducted competitor analysis to benchmark key UX patterns
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Facilitated multidisciplinary ideation sessions with devs, researchers, and subject matter experts
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Designed wireframes and prototypes to explore and test optimised flows
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Led accessibility testing across devices and assistive technologies
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Prioritised enhancements based on development effort vs. business impact

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Result
We delivered measurable gains through targeted UX improvements:
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Error messaging enhancements
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Introduced top-level alerts, clearer field labels, and in-basket product error feedback
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Improved accessibility and clarity for customers
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+1.2% increase in conversion for users encountering errors
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£1.8M annual revenue impact
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Improved CTA visibility (Mobile/Tablet)
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Made “Continue to checkout” CTA more visible, especially for large baskets
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Simplified progression for mobile users
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+1.1% increase in mobile conversion
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£6.6M annual revenue impact