An emscripten build of libheif distributed as an npm module for the browser.
npm i libheif-web
Download libheif.min.js from the libheif v1.14.0 release and put it in your project's assets
folder.
Use following code to set url for libheif.
import {useUrl} from 'libheif-web';
useUrl('assets/scripts/libheif.min.js');
If you skip this step the url will automatically point to libheif.min.js
import {convertHeif, convertAllOfHeif} from 'libheif-web';
const pngImage = await convertHeif(heicFile, 'filename.png', 'image/png');
const images = await convertAllOfHeif(heicFile);
const firstPng = await images[0].convert('filename.png', 'image/png');
const secondPng = await images[1].convert('filename.png', 'image/png');