We have a document library with images.

The end goal is to convert the image to base64 and store it in a custom column.

There are more than 700 images in the document library that need to be converted to base64 to be used in pdf with jspdf plugin , However doing it manually would be time consuming.

The below javascript function that works as expected

function getBase64Image(dLogo) {

  var canvas = document.createElement("CANVAS");
  var ctx = canvas.getContext("2d");
  ctx.clearRect( 0 , 0 , canvas.width, canvas.height );
  ctx.fillRect(0 , 0 , canvas.width, canvas.height);
  var img = new Image();
  img.crossOrigin = 'Anonymous';
  img.onload = function(){
   canvas.width = img.width;
   canvas.height = img.height;
   ctx.drawImage(img, 0, 0);
   var dataURL = canvas.toDataURL("image/jpeg");
   //return dataURL;
   document.getElementById("Base64").value = dataURL;
   canvas = null;
   img.src = dLogo;

Also created a PowerAutomate flow , However the base64 URL generated is different when compared with the one generated using javascript function and is not working with Jspdf.

Base64(Using Javascript) data:image/jpeg;base64,/9j/4AAQSkZJRgABAQAAAQABAAD/2wBDAAMCAgICAgMCAgIDAwMDBAYEBAQEBAgGBgUGCQg


Would appreciate if anyone here could let us know how these images could be converted to a workable base64 string and stored in a custom column against every image.

Thanks in advance


I convert image to base64 format with the following code:

<input id="inputFileToLoad" type="file" onchange="encodeImageFileAsURL();" />
<div id="imgTest"></div>
<script type='text/javascript'>
  function encodeImageFileAsURL() {

    var filesSelected = document.getElementById("inputFileToLoad").files;
    if (filesSelected.length > 0) {
      var fileToLoad = filesSelected[0];

      var fileReader = new FileReader();

      fileReader.onload = function(fileLoadedEvent) {
        var srcData = fileLoadedEvent.target.result; // <--- data: base64

        var newImage = document.createElement('img');
        newImage.src = srcData;

        document.getElementById("imgTest").innerHTML = newImage.outerHTML;
        alert("Converted Base64 version is " + document.getElementById("imgTest").innerHTML);
        console.log("Converted Base64 version is " + document.getElementById("imgTest").innerHTML);

And flow do the same thing, the base64 string is the same. enter image description here

  • Thank you for the help , in place of file input please use textinput and pass the url of the file , the base64 URLs would be different
    – Vivek
    Feb 18 at 12:11

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