Device Viewport Inspector

Not available to websites: iOS and Android do not expose system Text Size / Display size or Display Zoom (Standard vs Zoomed) to ordinary web pages. There is no supported API to read those settings directly.

The fields above are indirect hints: root font-size sometimes changes when the browser maps OS text settings to layout (behavior varies by browser and page CSS). Visual viewport scale mainly reflects pinch or page zoom relative to the layout viewport, not a labeled “Display Zoom” mode.