Walidator Validator.nu
Kod
<iframe src="javascript:(function(){
var form = document.createElementNS('http://www.w3.org/1999/xhtml', 'form');
form.enctype = 'multipart/form-data';
form.method = 'post';
form.acceptCharset = 'utf-8';
form.action = 'https://html5.validator.nu/';
form.innerHTML = '<input name="parser"/><input name="showsource" value="yes"/><textarea name="content"></textarea>';
form.parser.value = document.createElement('div').tagName == 'DIV' ? 'html' : 'xml';
form.content.value = '<!DOCTYPE html>\n<html>\n<head>\n<title>title</title>\n<meta charset="UTF-8" >\n</head>\n<body>\n</body>\n</html>';
if (document.documentElement) document.documentElement.appendChild(form);
else document.appendChild(form);
form.submit();
})()"
width="100%" height="577"></iframe>
Online SQL interpreter
phpmyadmin (demo)
https://demo.phpmyadmin.net/master-config/