PDF Generation in JavaScript: pdf-lib Library

What is pdf-lib and why is it needed?

pdf-lib is a powerful and lightweight library for creating and editing PDF documents in JavaScript (Node.js and browser). Unlike heavyweight solutions like Puppeteer or jsPDF, pdf-lib does not require a browser environment (Chromium) to be installed and works exclusively with native PDF structures. It is ideal for server-side generation of reports, invoices, certificates, and any other documents where full control over content is needed: text, fonts (including embedding), images, forms, annotations, and pages.

Installation

Installation via npm is simple:

npm install pdf-lib

Then import it into your project:

const { PDFDocument, rgb, StandardFonts } = require('pdf-lib');

Main Features

• Creating PDF from scratch — adding pages, text, images.
• Editing existing PDFs — copying pages, inserting text over them, merging documents.
• Working with fonts — support for standard fonts (Helvetica, TimesRoman) and embedding custom TTF fonts.
• Drawing shapes — lines, rectangles, ellipses with color and transparency settings.
• Forms and annotations — creating text fields, buttons, links.
• Export to Uint8Array — the result can be saved to a file or sent to the client.

Code Example on Node.js

Let's create a simple PDF with a title and an image:

const { PDFDocument, rgb } = require('pdf-lib');const fs = require('fs');

async function createPDF() {  const doc = await PDFDocument.create();  const page = doc.addPage([600, 400]);    // Text  page.drawText('Hello, World!', {    x: 50,    y: 350,    size: 30,    color: rgb(0, 0.53, 0.71),  });    // Rectangle  page.drawRectangle({    x: 50,    y: 200,    width: 200,    height: 100,    color: rgb(0.9, 0.1, 0.1),    borderColor: rgb(0, 0, 0),    borderWidth: 2,  });    // Embedding an image (PNG)  const imageBytes = fs.readFileSync('logo.png');  const image = await doc.embedPng(imageBytes);  page.drawImage(image, {    x: 300,    y: 250,    width: 100,    height: 100,  });    const pdfBytes = await doc.save();  fs.writeFileSync('output.pdf', pdfBytes);}

createPDF().catch(console.error);

When to use pdf-lib?

pdf-lib is the best choice if you are working in a Node.js (or browser) environment and need to:
- Quickly generate PDFs without launching a browser (saving memory and time).
- Embed custom fonts (e.g., for Cyrillic).
- Edit existing PDFs (add watermarks, merge documents).
- Create interactive forms.

Avoid pdf-lib if you need to render complex HTML/CSS into PDF (Puppeteer is better suited here) or work with large volumes of data (heavy PDFs can slow down performance).