Fair enough. I intended only to test the specific narrow claim OP made that you had quoted, which seemed to be about a local file test. This shows it is technic

Fair enough. I intended only to test the specific narrow claim OP made that you had quoted, which seemed to be about a local file test. This shows it is technically true that browsers are capable of detecting UTF-8, but only in one narrow situation and not the one that's most interesting. Indeed, in the Chromium source code we can see a special case for local files with some comment explanation. https://github.com/chromium/chromium/blob/dea8b2608dd5d95e3869febc8b13d425291c19ef/third_party/blink/renderer/platform/text/text_encoding_detector.cc#L57-L85 https://github.com/chromium/chromium/blob/dea8b2608dd5d95e38...