UMUX-LITE

UMUX-LITE, introduced by James Lewis, Brian Utesch, and Deborah Maher in 2013, is the shortest standardized measure of perceived usability in common use. It keeps only the two positive items from the UMUX, making it easy to embed almost anywhere.

The Two Items

Respondents rate two statements on a 7-point scale:

• "This system's capabilities meet my requirements" (usefulness)
• "This system is easy to use" (ease of use)

Together these cover the two ideas that most strongly drive overall usability judgments. Reported reliability is solid for such a short instrument (around .82 to .83).

Relationship to SUS

Raw UMUX-LITE scores track SUS closely but tend to sit slightly below it, by a few points on average, not above it. The original paper published a regression adjustment to map UMUX-LITE onto the familiar 0-100 SUS scale, but its own authors no longer recommend it: it seriously underestimates SUS at higher levels of perceived usability. Report the unadjusted score, and do not treat it as interchangeable with a SUS number.

When to Use

UMUX-LITE shines in product analytics surveys, in-app micro-surveys, and any context where every extra question lowers completion. It gives a defensible usability number at the lowest possible cost in respondent effort.

Important Notes

Two items cannot diagnose what is wrong, only signal how usable a product feels. Use UMUX-LITE for tracking and benchmarking, then follow up with qualitative work or task-based testing to understand the why.