HTML Checking for Large Sites

In order to define the charset encoding of an HTML document, both of these options are valid, but only one of them must appear in the document:

<!-- This is the preferred way -->
<meta charset="UTF-8">

<!-- This is the older way, also valid -->
<meta http-equiv="content-type" content="text/html; charset=UTF-8">

Read about specifying the character encoding

A <meta> tag has been found in the document stating that the charset is windows-1251, but it actually is utf-8. You should update the tag to reflect the actual encoding of the document, for example:

<meta http-equiv="Content-Type" content="text/html; charset=utf-8">

A <meta> tag has been found in the document stating that the charset is windows-1252, but it actually is utf-8. You should update the tag to reflect the actual encoding of the document, for example:

<meta http-equiv="Content-Type" content="text/html; charset=utf-8">

A character has been found in the document that is not allowed in the charset encoding being used.

The document has been declared to use a windows-1251 charset but the actual contents seems to be utf-8. You should update the charset to that like in this example:

<meta http-equiv="Content-Type" content="text/html; charset=utf-8">

In HTML5 you’re encouraged to use Unicode (UTF-8) character encoding rather than a legacy character encoding such as Latin1 (Windows-1252 or ISO 8859-1).

In short, it can be just a matter of using <meta charset="utf-8"/> in your document, but you should also ensure that your pages are also saved and served as UTF-8.

• W3C: Changing an HTML page to Unicode