Polyfill Requirements

The LI.FI Widget uses modern JavaScript APIs that may not be supported in older environments. Partners integrating the Widget may need to add polyfills if they need to support older browsers.

Polyfills are only needed if you must support an environment where an API below is marked ❌. The polyfill packages/imports in this page are suggestions—you can use any equivalent polyfill solution as long as it provides the same API behavior.

Browser & API Support

API	Polyfill	iOS 15.0-15.3	iOS 15.4+	iOS 16.0+	Chrome 92+	Firefox 92+	Safari 15.4+	Safari 16.0+	Samsung 16.0+
`structuredClone()`	`core-js/actual/structured-clone`	❌	✅	✅	✅	✅	✅	✅	✅
`Array.at()`	`core-js/actual/array/at`	❌	✅	✅	✅	✅	✅	✅	✅
`Object.hasOwn()`	`core-js/actual/object/has-own`	❌	✅	✅	✅	✅	✅	✅	✅
`Array.findLast()`	`core-js/actual/array/find-last`	❌	✅	✅	✅	✅	✅	✅	✅
`Array.findLastIndex()`	`core-js/actual/array/find-last-index`	❌	✅	✅	✅	✅	✅	✅	✅
`Array.toSpliced()`	`core-js/actual/array/to-spliced`	❌	❌	✅	✅	✅	❌	✅	✅
`Array.toSorted()`	`core-js/actual/array/to-sorted`	❌	❌	✅	✅	✅	❌	✅	✅
`Array.with()`	`core-js/actual/array/with`	❌	❌	✅	✅	✅	❌	✅	✅

Legend: ❌ Not supported (requires polyfill) | ✅ Fully supported

Polyfill Setup (Examples)

Install a polyfill library

npm install core-js

Import polyfills (choose one approach)

Option A: simplest (larger bundle)

// Place at the very beginning of your app entry point (before importing the Widget)
import 'core-js'

Option B: only what you need (smaller bundle)

// Place at the very beginning of your app entry point (before importing the Widget)
import 'core-js/actual/structured-clone'
import 'core-js/actual/array/at'
import 'core-js/actual/object/has-own'
import 'core-js/actual/array/find-last'
import 'core-js/actual/array/find-last-index'
import 'core-js/actual/array/to-spliced'
import 'core-js/actual/array/to-sorted'
import 'core-js/actual/array/with'

Getting Started

Basic Setup

Advanced

Widget Light (iframe)

Misc.

Polyfill Requirements

Browser & API Support

Polyfill Setup (Examples)

Install a polyfill library

Import polyfills (choose one approach)

​Browser & API Support

​Polyfill Setup (Examples)

​Install a polyfill library

​Import polyfills (choose one approach)

Browser & API Support

Polyfill Setup (Examples)

Install a polyfill library

Import polyfills (choose one approach)