index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=5">
    <title>PDF Viewer</title>
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <style type="text/css">
        canvas {
            width: 100%;
            border: 1px solid black;
        }
    </style>
    <script type="text/javascript" src="pdf.min.js"></script>
    <script type="text/javascript">
        const url = location.search.substring(1);

        PDFJS.cMapUrl = 'cmaps/';
        PDFJS.cMapPacked = true;

        let pdfDoc = null;

        function createPage() {
            const div = document.createElement('canvas');
            document.body.appendChild(div);
            return div;
        }

        function renderPage(num) {
            pdfDoc.getPage(num).then((page) => {
            let scale = 2;
            let viewport = page.getViewport(scale);
            let canvas = createPage();
            let ctx = canvas.getContext('2d');

            canvas.height = viewport.height;
            canvas.width = viewport.width;

            let renderTask = page.render({
                canvasContext: ctx,
                viewport
            });
            renderTask.then(() => {
                if(num < pdfDoc.numPages) {
                    renderPage(num+1);
                }
            });
        });
        }

        PDFJS.getDocument(url).then((pdf) => {
            pdfDoc = pdf;
            renderPage(1);
        });
    </script>
</head>
<body>
</body>
</html>