Codemirror HTML Linter
https://github.com/mikethedj4/html-lint-for-codemirror
by toubia95
HTML
<script src="https://codemirror.net/lib/codemirror.js"></script>
<script src="https://codemirror.net/mode/xml/xml.js"></script>
<script src="https://codemirror.net/mode/htmlmixed/htmlmixed.js"></script>
<script src="https://codemirror.net/addon/dialog/dialog.js"></script>
<script src="https://codemirror.net/addon/lint/lint.js"></script>
<script src="https://codemirror.net/addon/lint/html-lint.js"></script>
<link rel="stylesheet" href="https://codemirror.net/lib/codemirror.css">
<link rel="stylesheet" href="https://codemirror.net/addon/lint/lint.css">
<link rel="stylesheet" href="https://codemirror.net/addon/fold/foldgutter.css">
<script src="http://htmlhint.com/js/htmlhint.js"></script>
<script src="https://htmlhint.com/js/htmlhint.js"></script>
<textarea id="editor">
<html>
<head>
<title>site name</title>
<meta charset=utf-8>
<meta name='viewport' content="initial-scale=1.0">
</head>
<body>
<span id="hello">hello </span>
</body>
</html>
</textarea>
JavaScript
// Initialize CodeMirror editor
var editor = CodeMirror.fromTextArea(document.getElementById("editor"), {
mode: "text/html",
tabMode: "indent",
styleActiveLine: true,
lineNumbers: true,
lineWrapping: true,
autoCloseTags: true,
dragDrop : true,
lint: true,
gutters: ["CodeMirror-linenumbers", "CodeMirror-lint-markers"]
});