@charset

The @charset CSS rule specifies the character encoding used in the style sheet. This syntax is useful when using non-ASCII characters in some CSS properties, like content. Although the first character in @charset is the @ symbol, it is not an at-rule. It is a specific byte sequence that can only be placed at the very beginning of a stylesheet. No other characters, except the Unicode byte-order mark, are allowed before it. It also does not follow normal CSS syntax rules such as use of quotes or whitespace.

If a @charset is not recognized as the charset declaration, it is parsed as a normal at-rule. The CSS syntax module deprecates this fallback behavior, defining it as an unrecognized legacy rule to be dropped when a stylesheet is grammar-checked.

As there are several ways to define the character encoding of a style sheet, the browser will try the following methods in the following order (and stop as soon as one yields a result):

1. The value of the Unicode byte-order character placed at the beginning of the file.
2. The value given by the charset attribute of the Content-Type: HTTP header or the equivalent in the protocol used to serve the style sheet.
3. The @charset CSS declaration.
4. Use the character encoding defined by the referring document: the charset attribute of the <link> element. This method is obsolete and should not be used.
5. Assume that the document is UTF-8.

@charset "UTF-8";
@charset "iso-8859-15";

@charset "<charset>";

@charset "UTF-8"; /* Set the encoding of the style sheet to Unicode UTF-8 */

@charset 'iso-8859-15'; /* Invalid, wrong quotes used */
@charset  "UTF-8"; /* Invalid, more than one space */
 @charset "UTF-8"; /* Invalid, there is a character (a space) before the declarations */
@charset UTF-8; /* Invalid, the charset is a CSS <string> and requires double-quotes */