Browse - Programming Tips - Firefox: The character encoding of the HTML document was not declared. The document will render with garbled text in some browser configurations if the document contains characters from outside the US-ASCII range. The character encoding of the page must be declared in the document or in the transfer protocol.

Date: 2018mar19
Product: Firefox
Language: html

Q. Firefox: The character encoding of the HTML document was not declared. The document will render with garbled text in some browser configurations if the document contains characters from outside the US-ASCII range. The character encoding of the page must be declared in the document or in the transfer protocol.

A.  After your <!DOCTYPE html> line add:

<meta charset="utf-8" />
Or whatever character set your page is encoded it.