PDF Generation in JavaScript: pdf-lib Library

What is pdf-lib and why is it needed?

pdf-lib is a powerful and pure JavaScript library for creating and modifying PDF documents on the server side (Node.js) and in the browser. Unlike heavyweight solutions like Puppeteer, pdf-lib does not require installing a browser or external dependencies. It works directly with the PDF specification, making it an ideal choice for generating simple to moderately complex documents: reports, invoices, certificates, forms, and contracts.

Installation

To install it in a Node.js project, run the command:

npm install pdf-lib

The library has no native dependencies and is compatible with Node.js 10+.

Main Features

Creating PDFs from scratch (blank pages, text, images, font embedding).
Editing existing PDFs (extracting pages, inserting, deleting, rotating).
Working with forms (filling fields, creating checkboxes and radio buttons).
Support for Unicode and custom fonts (TTF, OTF).
Adding metadata (author, title, date).
Export to ArrayBuffer, Uint8Array, or Blob.

JavaScript Code Example (Node.js)

Below is a simple example of creating a PDF with text 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]);    // Adding text  page.drawText('Hello, World!', {    x: 50,    y: 350,    size: 30,    color: rgb(0, 0.53, 0.71),  });    // Embedding a font (optional)  const fontBytes = fs.readFileSync('./fonts/roboto.ttf');  const font = await doc.embedFont(fontBytes);  page.drawText('Custom Font', {    x: 50,    y: 300,    size: 20,    font: font,  });    // Saving  const pdfBytes = await doc.save();  fs.writeFileSync('output.pdf', pdfBytes);  console.log('PDF created!');}

createPDF().catch(console.error);

This code creates a document with two lines, one of which uses an embedded font. To work with images, use doc.embedPng() or doc.embedJpg().

When to use pdf-lib

You need to quickly generate a PDF without launching a browser.
The document does not contain complex layouts (tables, columns) — for that, templating engines like Puppeteer are better suited.
A lightweight library with a minimal size (~500 KB) is required.
You are working with forms or editing existing PDFs.

Conclusion

pdf-lib is an excellent choice for projects that require PDF generation on Node.js without unnecessary dependencies. It is easy to learn, well-documented, and supports all basic operations. For complex layouts, consider Puppeteer or jsPDF, but for 80% of tasks, pdf-lib will be more than sufficient.