"interactive-widget" is a new property in the viewport <meta> tag that allows control over how and if the viewport is resized when the virtual keyboard on mobile is shown. In 2022, Chromium for Android changed its behavior regarding this to match the behavior of Safari on iOS [1], while also implementing the "interactive-widget" property so that developers can opt out of this new behavior.

Specification: https://drafts.csswg.org/css-viewport-1/#interactive-widget-section

On WebKit-based mobile browsers (i.e. all browsers on iOS), there remains no option to make the viewport resize to the actual visible region when a virtual keyboard is shown; The keyboard simply overlays the webpage with no option for opt-out. In most situations (especially when building web-based chat applications, rich text editors, etc.), it is desirable that the viewport changes to the actual size instead of the keyboard just overlaying the content and scrolling the page.

[1]: https://developer.chrome.com/blog/viewport-resize-behavior/

Related WebKit bugs:
- https://bugs.webkit.org/show_bug.cgi?id=176205
- https://bugs.webkit.org/show_bug.cgi?id=230225