I have the below HTML:

    <lightning-button onclick={generateData} label="Generate PDF"></lightning-button>

<iframe id="pdfFrame" src="/resource/pdfjs/web/viewer.html" width="100%" height="100%" class="pdfFrame"


import { LightningElement } from 'lwc';
import { loadScript } from "lightning/platformResourceLoader";
import JSPDF from '@salesforce/resourceUrl/jspdf';
import getContacts from '@salesforce/apex/PdfGenerator.getContactsController';

export default class JspdfDemo extends LightningElement {
    contactList = [];
    headers = this.createHeaders([

    renderedCallback() {
            loadScript(this, JSPDF)

    generatePdf() {
        const { jsPDF } = window.jspdf;
        const doc = new jsPDF({
            encryption: {
                userPassword: "user",
                ownerPassword: "owner",
                userPermissions: ["print", "modify", "copy", "annot-forms"]
                // try changing the user permissions granted

        doc.text("Hi I'm Matt", 20, 20);
        doc.table(30, 30, this.contactList, this.headers, { autosize: true });

    generateData() {
        getContacts().then(result => {
            this.contactList = result;

    createHeaders(keys) {
        var result = [];
        for (var i = 0; i < keys.length; i += 1) {
                id: keys[i],
                name: keys[i],
                prompt: keys[i],
                width: 65,
                align: "center",
                padding: 0
        return result;

This is the JS PDF librarythat I am using as a static resource:

After clicking the button it successfully downloads the PDF file.

But instead of downloading the file, I need to display the PDF file using iframe on salesforce I created iFrame tag in the HTML and tried below JS

this.template.querySelector('iframe').contentWindow.postMessage(this.pdfData, window.location.origin);

I tried passing blob or base64 as below

this.pdfData = doc.output('blob);


this.pdfData = new Blob([doc.output('blob')], { type: 'application/pdf' });


this.pdfData = doc.output('datauristring');

But the above did not work as expected, and also the generate PDF button doesn't work on salesforce 1 mobile app, can someone please suggest how to display the PDF on salesforce on both mobile and desktop view instead of downloading it. The other solution I am thinking of is saving this PDF to a content document and then use the content document to display the PDF file, but it would be a lot better if the iframe solution works so that we can eliminate server-side call.


I am not able to save the file to the content document also I have created another thread for that Saving PDF file to content document saves as black pages

screenshot of the page:

enter image description here

  • Can you check with this similar implementation? May 4 '21 at 8:50
  • Thank you for your comment, this is about showing the PDF file from the content document on the browser but in my case, I have to generate the file and then display it on the iframe.
    – gs650x
    May 4 '21 at 8:52
  • In that case this post could provide more insight on showing the pdf in same tab or opening in a new tab. For iframe,I still suspect whether it would be possible or not. May 4 '21 at 9:48
  • Thank you so much for your kind help here but none of the solutions suggested in the above forum worked so I am going with the content document approach, could you please take a look into this salesforce.stackexchange.com/questions/342163/… thread where it is not saving the file properly.
    – gs650x
    May 4 '21 at 11:01
  • @gs650x I am currently working on showing pdf in lwc but in my case I am getting base64data for pdf file and I M showing it in iFrame using pdfjs library. I am on phone but I will link my question and answer in sometime. I had hard time only with postMessage as lwc wasnt able to find the iframe. May 4 '21 at 12:38

Update your postMessage in iframe to below,

this.template.querySelector('iframe').contentWindow.postMessage(this.pdfData, window.location.origin);

for me Origin fixed the issue in iframe.

  • thank you for your answer, but unfortunately, this is not working.
    – gs650x
    May 4 '21 at 13:18
  • is your pdfjs loading a pdf viewer? that would be a big one as atleast the pdf viewer should be able to load if the library has been imported correctly. May 4 '21 at 13:20
  • yes it is loading, adding a screenshot to the question.
    – gs650x
    May 4 '21 at 13:22
  • did you try to console pdfData, is it correct base64 format string? May 4 '21 at 13:24
  • can you see if that same base64 you are generating is able to generate PDF here May 4 '21 at 13:25

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