Character encoding not declared in html document

I have a file that I am getting a very weird error on. The error is:

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 to be declared in the document or 
in the transfer protocol.

the file this comes from is (indexmws.php):

session_start();
if(!isset($_SESSION['validUser']) || $_SESSION['validUser'] !== true){
header('Location: loginmws.php');
}

include_once('db.php');
include_once('amazonmws.php');
include_once('decidemws.php');
include_once('author.php');
include_once('amazonPricingMWS.php');

?>

<!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" xml:lang="en" lang="en">
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
    <title>Decision Maker</title>

This is an exact duplicate of a file that does not throw the error (index.php)with the exception of adding amazonPricingMWS.php and redirecting to pages with mws.php in the title:

session_start();
if(!isset($_SESSION['validUser']) || $_SESSION['validUser'] !== true){
header('Location: login.php');
}

include_once('db.php');
include_once('amazon.php');
include_once('decide.php');
include_once('author.php');

?>

<!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" xml:lang="en" lang="en">
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
    <title>Decision Maker</title>

can anyone explain to me why I am getting this error in indexmws.php?

回答1:

The error is coming because the browsers expect the encoding format in the first 1024 bytes of the file. It may be the case that there is some content being outputted by the included files in the first case.

The browsers now buffer the first 1024 bytes of the file to check for the character encoding. If the encoding description is not encountered in the first 1024 bytes, this warning is displayed.

In your case, you can use a php header for specifying the content type before the other files are included:

header('Content-type: text/html; charset=utf-8');

For more information, read this: http://gtmetrix.com/specify-a-character-set-early.html

回答2:

I had similar problem But teh exact reason behind this was that I missed following to add

<meta content="utf-8" http-equiv="encoding">

in head tag after

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