JSFiddle - React, Tailwind, and code Playground
HTML
<input type="file" id="foo">
<input type="file" id="bar" multiple>JavaScript
console.log('supports multiple?', 'multiple' in document.createElement('input'));
console.log('multiple files (foo)?', document.getElementById('foo').multiple);
console.log('multiple files (bar)?', document.getElementById('bar').multiple);