What are the most common UX mistakes that impact conversions and engagement?

The most damaging UX mistakes for conversions are unclear page purpose (the user cannot tell within 5 seconds what the page offers and why it matters to them), friction-heavy forms that ask for unnecessary information upfront, and missing or poorly placed CTAs that leave users unsure of the next step.

Engagement suffers when content is not structured for scannable reading, when internal linking is weak and users hit dead ends, and when search functionality is absent or returns poor results on content-heavy sites. UX mistakes are often invisible to designers but highly visible in behavioral data: scroll maps showing 90% abandonment before the CTA, or click maps revealing users clicking on non-clickable elements are signals that UX decisions need revisiting.