How to find character encoding of a text file

Is it UTF8, ISO-8859-1, or UTF16-LE? How do you know which encoding a text file uses?

Unfortunately, it's not so easy to find out. Unicode has been around for more than 15 years and there is one program called Excel that still exports CSV files in its own fancy ISO-8859-1 (Latin-1) encoding that is bound to mess up pretty much anything if you have some characters not in the US keyboard. But of course you didn't know what encoding the CSV file is, even after almost pulling your hairs off googling for answer.

So, why bother about encoding? It's because my program can't read it if it's not converted to UTF-8. After trying many text editors hoping that it has a feature to show the current encoding, it finally dawned on me that there is this thing called Firefox which seems to recognize a file's character encoding.

Here's how to do it. Open the file in Firefox, then go to View, then choose Character Encoding. The selected one should be the encoding of the text file.