<!DOCTYPE html>
<html>
  <head>
    <meta http-equiv="Content-type" content="text/html; charset=utf-8"/>
    <title>{%=o.htmlWebpackPlugin.options.title || 'Webpack App'%}</title>
  </head>
  <body>
    {% for (var chunk in o.htmlWebpackPlugin.assets) { %}
    <script src="{%=o.htmlWebpackPlugin.assets[chunk]%}"></script>
    {% } %}
  </body>
</html>

<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8">
    <title>{%=o.htmlWebpackPlugin.options.title || 'Webpack App'%}</title>
  </head>
  <body>
    {% for (var chunk in o.htmlWebpackPlugin.assets) { %}
    <script src="{%=o.htmlWebpackPlugin.assets[chunk]%}"></script>
    {% } %}
  </body>
</html>

Set charset by latest HTML 5 spec
Set charset by latest HTML 5 spec