Lately I had a problem with a page which was including two JSON scripts, one encoded in UTF-8 and the other encoded in ISO-8859-1. In some circumstances (and in some browsers) the strings where not showed correctly. Hunting down the problem required a good dose of my favourite tool wget -S where the -S option causes the http response headers to be printed on stderr. My conclusions are that: if a page uses a certain encoding (as specified by the charset on the page and/or the Content-Type http header) the included javascript will be handled with the same type of encoding if nothing else is specified In Firefox, if the http response of the javascript contains the "Content-Type" header with a charset value, the file will be treated as using this encoding In Internet Explorer 6 (and 7?) the http headers are ignored and you must explicitly use the charsets attribute of the script tag to force the correct encoding In other words, to make a script inclusion cross-brows