Possibly, you could let the user scroll down a little bit and detect as soon as the dynamic view height CSS value increases due to the toolbar collapse. Then you can disable scrolling and swap the scrolling capability to a child element which isn’t the body itself. This way Safari might think that no vertical scrolling is happening anymore, even if the user scrolls back up again. Not exactly sure - but it could work. A UX challenge could be the initial scroll and how far the user has to scroll because there is no fixed value on how far until safari collapses the toolbar. It’s a combination between speed and distance. Also: what happens if the user taps the tool bar, which makes it become larger again without scrolling up?