Safari Extension

Safari Extensions: Extend the Safari browser experience on macOS, iOS, and iPadOS using familiar web technologies and the WebExtension API.

Safari Extensions deliver custom functionality directly to the Safari browser: this is how you enhance the user’s web experience. Developers build these extensions primarily with standard web technologies (HTML, CSS, JavaScript) and leverage the popular WebExtension API for cross-browser compatibility. Crucially, extensions are packaged within a containing app (via Xcode) and distributed exclusively through the App Store, ensuring a secure, unified distribution model. They operate across the Apple ecosystem: macOS, iOS 15+, and iPadOS 15+ are all supported, allowing for powerful features like content blocking and web page modification.

https://developer.apple.com/documentation/safariservices/safari_web_extensions