Can’t use forEach with Filelist
A FileList is not an Array, but it does conform to its contract (has length and numeric indices), so we can “borrow” Array methods: Array.prototype.forEach.call(field.photo.files, function(file) { … }); Since you’re obviously using ES6, you could also make it a proper Array, using the new Array.from method: Array.from(field.photo.files).forEach(file => { … });