WebView

Each platform has one: Android System WebView (based on Chromium and updated through Google Play), WKWebView on iOS and macOS (Safari's WebKit engine), WebView2 on Windows (Microsoft Edge's engine) and WebKitGTK on Linux. Apps use them for help pages, checkout flows and embedded content, and frameworks such as Capacitor, Cordova and Tauri use them to run the entire interface.

The app can talk to the page through a JavaScript bridge, which is useful but also a risk: a WebView that loads untrusted pages and exposes native functions to them can be abused. Google blocks its sign-in inside embedded WebViews, and OAuth guidance calls for the system browser (Custom Tabs on Android, ASWebAuthenticationSession on iOS) instead.