It is the most-used single-byte character encoding in the world. , 0.3% of all web sites declared use of Windows-1252, but at the same time 1.4% used ISO 8859-1 (while only 0.9% of top-1000 websites), which by HTML5 standards should be considered the same encoding, so that 1.7% of web sites effectively use Windows-1252. Pages declared as US-ASCII would also count as this character set. An unknown (but probably large) subset of other pages only use the ASCII portion of UTF-8, or only the codes matching Windows-1252 from their declared character set, and could also be counted.