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phphtmlcharacter-encodingdtd

Do I need to declare content type/charset in both HTML and PHP?

If the content type and character set are declared in the PHP header, is there a reason to have them again in the usual HTML DTD?

<?php ob_start( 'ob_gzhandler' );
 header('Content-type: text/html; charset=utf-8'); ?> // here
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> // and here
...
Solution

  • If you are sending the charset in the headers, the is no need to repeat it in the HTML markup.

    It is better to send this information in one place (DRY principle), as if the charsets conflict (ie. a header with UTF-8 and a meta with iso-8859-1), the browser will probably go to quirks mode.

    Having said that, some automated tools (web scrapers) may not look at the header and deduce the page encoding only by the meta tag.

    It is important to keep both the header and meta tag the same for each page - mixing different charsets may confuse browsers and cause display issues.