81% of our mobile users hold their phone in one hand.

We analyzed touch data across 900,000 mobile sessions.

One-handed use: 81%

Two-handed: 14%

Unknown: 5%

Median thumb reach zone: bottom 40% of screen

Interactions in top 25% of screen: 9% of all taps

Most of our primary actions were in the top right corner, which was the hardest place to reach with a thumb. Users were either using two hands, stretching, or not tapping those actions at all. We had been designing for a screen, not a hand.

We moved primary actions to the bottom third and added a bottom sheet for secondary actions. Tap rate on primary actions rose 37%, and one-handed task completion rose 29%.

Where are your most important actions, and can a thumb reach them?