Remote and Local Files   Reference

Remote file

function fileSelect() {
    fetch(remote.value).then(r => r.blob())
    .then(checkFiles) //called with Blob b
}
function checkFiles(b) {
    let toStr = f => f.name+' '+f.type
    let equals = f =>
        f.size==b.size && f.type==b.type
    let a = [...local.files]  //to Array
    out.innerText = a.map(toStr).join('\n')
        +'\n\n'+ a.length+' items checked, '
    let [found] = a.filter(equals)
    out.innerText += found ?
            found.name+' is the same'
          : 'all files are different'
}