In-App Browser
Also known as: webview, in-app browser
The mini-browser inside apps like Instagram or TikTok that opens links without leaving the app.
In-app browsers are a WebView the host app fully controls. That means the app can inject JavaScript, watch what you type, read the URLs you visit and, in some documented cases, insert tracking scripts into every page.
For anything sensitive — logins, banking, purchases — open the link in your real browser via the 'Open in Safari/Chrome' option. It's the single quickest way to escape a hostile in-app browser.