text.html

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title>GET TEXT FROM UPLOADED PDF</title>
    <script type="text/javascript" src="/pdf.js"></script>
  </head>
  <body>
    <canvas id="the-canvas"></canvas>
    <script type="text/javascript">
      const BASE_URI = window.location.origin;

      PDFJS.disableWorker = true;

      var url;
      try {
        url = window.location.search.slice(5)
      } catch (e) {
        // console.log('use "?pdf=PDF-URI" like!')
      }

      PDFJS.workerSrc = `${BASE_URI}/pdf.worker.js`;

      function gettext (pdfUrl) {
        var pdf = PDFJS.getDocument(pdfUrl);
        return pdf.then(function(pdf) { // get all pages text
             var maxPages = pdf.pdfInfo.numPages;
             if (maxPages > 7) {
               maxPages = 7
             }
             var countPromises = []; // collecting all page promises
             for (var j = 1; j <= maxPages; j++) {
                var page = pdf.getPage(j);

                var txt = "";
                countPromises.push(page.then(function(page) { // add page promise
                    var textContent = page.getTextContent();
                    return textContent.then(function(text){ // return content promise
                        return text.items.map(function (s) { return s.str; }).join(''); // value page text
                    })
                }))
             }
             // Wait for all pages and join text
             return Promise.all(countPromises).then(function (texts) {
               return texts.join('');
             });
        });
        }
        // waiting on gettext to finish completion, or error
        gettext(url).then(function (text) {
          console.log(text);
        }, function (reason) {
          console.error(reason);
        });
    </script>
  </body>
</html>