UX Design KPI

Mike's Notes

This list of KPIs comes from Vitaly Friedman's free Smashing Magazine workshop on Inclusive Design Patterns, which was held this morning on Zoom.

Update

Some of the same material appeared in a later LinkedIn post in 2026 and has been added here.

Resources

• https://smashingconf.com/online-workshops/workshops/inclusive-design-patterns-vitaly-friedman/
• https://www.linkedin.com/posts/vitalyfriedman_ux-design-activity-7140641630507687936-YTI7/

References

• Reference

Repository

• Home > Ajabbi Research > Library > Subscriptions > Smashing Magazine
• Home > Handbook > 

Last Updated

25/01/2026

UX Design KPI

By: Vitaly Friedman

Smashing Magazine: 27/09/2024

Improve

• Accuracy of data ≈ 100%.
• Time to complete < 35s.
• Time to relevance < 30s.
• Frequency of errors < 3/visit (mistaps, double-clicks)
• Error recovery speed < 7s.
• Top tasks success > 80% (for critical tasks)
• System Usability Scale > 75 (overall usability)
• WCAG AA coverage ≈ 100% (accessibility)
• Core Web Vitals ≈ 100% (performance)

Measure

• Sales/marketing costs < $15K/w.

Reduce

• Flesch reading ease score > 60 (readability)
• “Turn-around” score < 1 week (frustrated users -> happy users)
• Service desk inquiries < 35/week (poor design -> more inquiries)
• Search query iterations < 3/query (to avoid dead-ends)
• Time to release/update < 14 days.
• Non-content on a page < 25%.
• Environmental impact < 0.3g/page request (sustainability)
• Onboarding time < 15 sec.

Others

• Application processing time < 2 weeks (online banking)
• Accessible Usability Scale (AUS) > 75 (accessibility)
• Acquisition costs < $15K/week (poor design -> high acquisition costs)
• Customers follow-up rate < 4% (quality of service desk replies)
• Default settings correction < 10% (quality of defaults)
• Fake email addresses < 5% (for newsletters)
• Filters used per session > 5 per user (quality of filtering)
• Feature adoption rate > 80% (usage of a new feature per user)
• Form input accuracy ≈ 100% (user input in forms)
• Presets/templates usage > 80% per user (to boost efficiency)
• Password recovery frequency < 5% per user (for auth)
• Rage and tap clicks rate ≈ 0% (for touch, mouse)
• Relevance of top 100 search requests > 80% (for top 3 results)
• Time to complete top tasks < 60s (for critical tasks)
• Time to first success < 90s (for onboarding) 
• Time to candidates < 120s (nav + filtering in eCommerce)
• Time to pricing quote < 2 weeks (for B2B systems)
• Time to top candidate < 120s (for feature comparison)
• Time to hit the limit of free tier < 7d (for upgrades)
• User frustration score < 10% (AUS + SUS/SUPR-Q + Lighthouse)

These KPIs aren’t chosen randomly. They are shaped together by designers, engineers, stakeholders and users, and they must be guided by user needs and aligned with business goals. I can’t emphasize that last part enough: design shouldn’t be seen as a standalone activity as it impacts all parts of business.

For a given project and a given design team, 3–4 KPIs will be most critical. If we work on search, then we can track the quality of search over time. If we work on filters, we track how many filters are used per session, and how effective they are. As we move to a new project, we track a new set of KPIs.

This requires engineering to implement mechanisms to track adoption, and as designers, we test our work in qualitative testing. And: whenever possible, I always prefer usability testing as surveys are incredibly difficult to get right.