Getting Started

Install

npm install happypdf

HappyPDF requires Node 22 or newer, and works in modern browsers, Deno and edge runtimes.

Your first document

import fs from 'node:fs';
import { PDFDocument, StandardFonts, rgb } from 'happypdf';

const pdfDoc = await PDFDocument.create();
const page = pdfDoc.addPage([595, 842]); // A4
const font = await pdfDoc.embedFont(StandardFonts.Helvetica);

page.drawText('Hello, world!', {
  font,
  x: 50,
  y: 750,
  size: 24,
  color: rgb(0.1, 0.1, 0.1),
});

fs.writeFileSync('hello.pdf', await pdfDoc.save());

Embedding a custom font

Unlike pdf-lib, there is no font engine to install and register. Pass the font bytes and HappyPDF shapes them with the bundled HarfBuzz:

const fontBytes = fs.readFileSync('NotoSansKhmer-Regular.ttf');
const khmer = await pdfDoc.embedFont(fontBytes, { subset: true });

page.drawText('សួស្តីពិភពលោក', { font: khmer, x: 50, y: 700, size: 24 });

subset: true embeds only the glyphs you actually used, which usually shrinks the file substantially.

Migrating from pdf-lib

pdfDoc.registerFontkit(...) still exists as a no-op, so existing code keeps working. You can delete the call whenever convenient.

Modifying an existing PDF

const existing = fs.readFileSync('input.pdf');
const pdfDoc = await PDFDocument.load(existing);

const [first] = pdfDoc.getPages();
first.drawText('Reviewed', { x: 50, y: 50, size: 12 });

fs.writeFileSync('output.pdf', await pdfDoc.save());

In the browser

<script src="https://unpkg.com/happypdf/dist/happypdf.min.js"></script>
<script>
  const { PDFDocument, StandardFonts } = happypdf;

  (async () => {
    const pdfDoc = await PDFDocument.create();
    const page = pdfDoc.addPage();
    const font = await pdfDoc.embedFont(StandardFonts.Helvetica);
    page.drawText('From the browser', { font, x: 50, y: 700, size: 20 });

    const bytes = await pdfDoc.save();
    const url = URL.createObjectURL(
      new Blob([bytes], { type: 'application/pdf' }),
    );
    window.open(url);
  })();
</script>

The bundle inlines the HarfBuzz WebAssembly, so there is nothing else to fetch.

Next steps

• Why HappyPDF — what this fork changes
• Fonts and Shaping — complex scripts, subsetting, variable fonts
• Wrapping and Alignment — maxWidth, align, justification
• Live Demos — runnable examples in your browser