Quick and dirty way to create and test HTML page
A functional HTML/CSS/JS editor in less than 400 bytes is all it takes to use a browser are a text editor for HTML/CSS/JS.data:text/html,<body oninput="i.srcdoc=h.value+'<style>'+c.value+'</style><script>'+j.value+'</script>'"><style>textarea,iframe{width:100%;height:50%}body{margin:0}textarea{width:33.33%;font-size:18}</style><textarea placeholder=HTML id=h></textarea><textarea placeholder=CSS id=c></textarea><textarea placeholder=JS id=j></textarea><iframe id=i>
If you want to read the code, check out index.html