In PHP, use: utf8_decode
Thsi converts the string with ISO-8859-1 characters encoded with UTF-8 to single-byte ISO-8859-1

In javascript, the following to to the same:

var decoded_content = self.utf8_decode(content);
self.scans.unshift({ date: +(Date.now()), content: decoded_content });

utf8_decode: function (str_data) {
// Converts a string with ISO-8859-1 characters encoded with UTF-8 to single-byte ISO-8859-1
var string = "", i = 0, c = c1 = c2 = 0;

	while ( i < str_data.length ) {
		c = str_data.charCodeAt(i);
		if (c < 128) {
			string += String.fromCharCode(c);
			i++;
		} else if((c > 191) && (c < 224)) {
			c2 = str_data.charCodeAt(i+1);
			string += String.fromCharCode(((c & 31) << 6) | (c2 & 63));
			i += 2;
		} else {
			c2 = str_data.charCodeAt(i+1);
			c3 = str_data.charCodeAt(i+2);
			string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
			i += 3;
		}
	}
	return string;

Having the same issue. Cyrillics are decoded into gibberish:

�анн�й к�пон �гене�и�ован

having same issues with korean language

Having the same issue. Cyrillics are decoded into gibberish:

�анн�й к�пон �гене�и�ован

Проблема с этом куске

@alekciy Thank you for the tip, I have added utf8 decoder in that line and it worked.

Though this might not get merged. In case somebody needs this fix, you can clone the repo, apply the fix yourself and rebuild the package with:

npm install
./node_modules/.bin/gulp release

The instascan.min.js will appear in dist directory.

@alekciy Thank you for the tip, I have added utf8 decoder in that line and it worked.

А если cp1251? Например, платежки по ГОСТ Р 56042-2014 формат ST00011. В идеале добавить бы детектор кодировки.

@alekciy I don't think there is a reliable way to detect text encoding, especially when it's CP encodings. It would probably be better to add an encoding parameter to the Scanner class.