It does not make sense to have a string without knowing what encoding it uses. You can no longer stick your head in the sand and pretend that “plain” text is ASCII.
UniView is a Web-based application for working with Unicode characters. No need to install anything – just open in a browser. You can look up or find characters (using graphics or fonts) and related information, view whole character blocks or custom ranges, select characters to paste into your document, paste in and discover unknown characters, search for characters using regular expressions, do hex/dec/ncr conversions, highlight character types, etc. etc. It supports Unicode 14.0 and is written with Web Standards to work on a variety of browsers.