index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js" type="text/javascript"></script>
    <title>Google API Code Extractor</title>
</head>
<body>
    <!-- Print JS scrip output here -->
    <div id="input">
        <h1>Google API Code Extractor</h1>
        <p>Enter the URL of the Google API page you want to extract the code from.</p>
        <input type="text" id="url" placeholder="Enter URL">
        <button id="submit">Submit</button>
        
    </div>
    <div id="output">
        <p>The Clean URL: "<span id="clean_url"></span>"</p>
        <p>The Code: "<span id="code"></span>"</p>
        <p>The State: "<span id="state"></span>"</p>
        <p>The Scope: "<span id="scope"></span>"</p>
    </div>

    
</body>
<script>
    function parseURLParams(url) {
        var queryStart = url.indexOf("?") + 1,
            queryEnd   = url.indexOf("#") + 1 || url.length + 1,
            query = url.slice(queryStart, queryEnd - 1),
            pairs = query.replace(/\+/g, " ").split("&"),
            parms = {}, i, n, v, nv;
    
        if (query === url || query === "") return;
    
        for (i = 0; i < pairs.length; i++) {
            nv = pairs[i].split("=", 2);
            n = decodeURIComponent(nv[0]);
            v = decodeURIComponent(nv[1]);
    
            if (!parms.hasOwnProperty(n)) parms[n] = [];
            parms[n].push(nv.length === 2 ? v : null);
        }
        return {'url': decodeURIComponent(url), 'parms': parms};
    }

    $(document).ready(function(){
        $("#submit").click(function(){
            var url = document.getElementById('url').value;

            console.log(url);
            var url = parseURLParams(url);
            document.getElementById("clean_url").innerHTML = url.url;
            document.getElementById("code").innerHTML = url.parms.code;
            document.getElementById("state").innerHTML = url.parms.state;
            document.getElementById("scope").innerHTML = url.parms.scope;
            document.getElementById('url').value = "";
        });
    });


</script>
</html>