This is my page header:
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1, minimum-scale=1.0, maximum-scale=1.0, user-scalable=no" />
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
...
As you can see the charset is set to utf-8 but Chrome/Firefox does not print the page as utf-8. I guess that is because the server sends this header:
Content-Type:text/html; charset=ISO-8859-15
How can I overwrite this header from my html page?
You can’t.
HTTP headers have priority over meta elements that claim to be equivalent.
Fix your server settings so it sends the correct content-type.