The PDF engine for modern JavaScript

Create, parse, fill, merge, sign, and manipulate PDF documentsin Node, Deno, Bun, Cloudflare Workers, and every browser.

Get Started · Features · API · Why This?

Quick Start

npm install modern-pdf-lib

import { createPdf, PageSizes, rgb } from 'modern-pdf-lib';

const doc = createPdf();
const page = doc.addPage(PageSizes.A4);

page.drawText('Hello from modern-pdf-lib', {
  x: 50,
  y: 750,
  size: 28,
  color: rgb(0.13, 0.13, 0.13),
});

const bytes = await doc.save();          // Uint8Array
const stream = doc.saveAsStream();       // ReadableStream
const blob = await doc.saveAsBlob();     // Blob (browsers)

CDN (no install)

Use directly in the browser via CDN — no bundler required:

<script type="module">
  import { createPdf, PageSizes, rgb } from 'https://cdn.jsdelivr.net/npm/modern-pdf-lib/dist/browser.mjs';

  const doc = createPdf();
  const page = doc.addPage(PageSizes.A4);
  page.drawText('Hello from CDN!', { x: 50, y: 750, size: 24, color: rgb(0, 0, 0) });
  const bytes = await doc.save();
  console.log('PDF size:', bytes.length, 'bytes');
</script>

Also available via:

• unpkg: https://unpkg.com/modern-pdf-lib/dist/browser.mjs
• esm.sh: https://esm.sh/modern-pdf-lib

Script Tag (no modules)

For environments without ES module support, use the IIFE bundle which exposes a window.ModernPdf global:

<script src="https://cdn.jsdelivr.net/npm/modern-pdf-lib/dist/modern-pdf-lib.iife.js"></script>
<script>
  const { createPdf, PageSizes, rgb } = ModernPdf;

  const doc = createPdf();
  const page = doc.addPage(PageSizes.A4);
  page.drawText('Hello from script tag!', { x: 50, y: 750, size: 24, color: rgb(0, 0, 0) });
  doc.save().then(function (bytes) {
    console.log('PDF size:', bytes.length, 'bytes');
  });
</script>

Features

Create & Draw

• Pages, text, images, shapes, SVG paths
• TrueType & OpenType font embedding
• Automatic font subsetting
• JPEG / PNG image embedding
• Image optimization (JPEG recompression, dedup, grayscale)
• RGB, CMYK, grayscale colors
• Linear & radial gradients, tiling patterns
• Text layout (multiline, combed, auto-size)

Parse & Modify

• Load existing PDFs (encrypted too)
• Extract text with positions
• Fill & flatten AcroForm fields
• Merge, split, copy pages
• Add / remove / reorder pages
• Incremental saves

Secure & Compliant

• AES-256 / RC4 encryption & decryption
• Digital signatures (PKCS#7, visible/invisible, timestamps)
• CRL/OCSP revocation checking & certificate chain validation
• Incremental save with signature preservation
• Multi-signature chains, MDP certification, LTV archival
• Counter-signatures & field locking
• PDF/A-1b through PDF/A-3u validation
• Tagged PDF / PDF/UA accessibility
• Structure tree & marked content
• Redaction with content removal

Advanced

• QR codes & barcodes (9 formats)
• Table layout engine with pagination
• JPEG2000 (JPXDecode) image support
• WebP image embedding (lossy, lossless, alpha)
• TIFF image embedding (multi-page, CMYK, direct mapping)
• Image format auto-detection (PNG/JPEG/WebP/TIFF)
• Form field JavaScript evaluation & sandboxing
• Outlines / bookmarks
• Optional content layers (OCGs)
• File attachments & watermarks
• Linearization (fast web view)
• Browser helpers (download, blob, data URL)
• Service Worker & Web Worker support
• CLI: npx modern-pdf optimize

Why modern-pdf-lib?

Runtimes

| Runtime | Version | Status | |:---|:---|:---:| | Node.js | 25.7+ | Fully supported | | Deno | 1.40+ | Fully supported | | Bun | 1.0+ | Fully supported | | Cloudflare Workers | — | Fully supported | | Chrome / Edge | 109+ | Fully supported | | Firefox | 115+ | Fully supported | | Safari | 16.4+ | Fully supported |

API Surface

import { createPdf, loadPdf, PageSizes } from 'modern-pdf-lib';

// Create from scratch
const doc = createPdf();
doc.setTitle('Invoice #1042');
doc.setLanguage('en');

// Load existing
const existing = await loadPdf(pdfBytes, { password: 'secret' });

// Save
const bytes = await doc.save();
const stream = doc.saveAsStream();

const page = doc.addPage(PageSizes.LETTER);

page.drawText('Hello', { x: 50, y: 700, size: 24 });
page.drawImage(imageRef, { x: 50, y: 400, width: 200, height: 200 });
page.drawRectangle({ x: 50, y: 300, width: 100, height: 50, color: rgb(0, 0.5, 1) });
page.drawCircle({ x: 200, y: 325, radius: 25 });
page.drawSvgPath('M 0 0 L 100 0 L 50 80 Z', { x: 300, y: 300 });

// Standard fonts (no embedding needed)
const helvetica = doc.embedStandardFont('Helvetica');

// Custom TrueType / OpenType
const fontBytes = await readFile('Inter.ttf');
const inter = await doc.embedFont(fontBytes, { subset: true });

page.drawText('Custom font', { x: 50, y: 500, font: inter, size: 18 });

const form = doc.getForm();

form.getTextField('name').setText('Jane Doe');
form.getCheckbox('agree').check();
form.getDropdown('country').select('Canada');

form.flatten(); // Burn values into page content

import { mergePdfs, splitPdf, copyPages } from 'modern-pdf-lib';

const merged = await mergePdfs([pdf1Bytes, pdf2Bytes]);
const pages = await splitPdf(pdfBytes, [
  { start: 0, end: 4 },   // Pages 1-5
  { start: 5, end: 9 },   // Pages 6-10
]);

const bytes = await doc.save({
  userPassword: 'reader',
  ownerPassword: 'admin',
  permissions: { printing: true, copying: false },
});

import { signPdf, verifySignatures } from 'modern-pdf-lib';

const signed = await signPdf(pdfBytes, 'Signature1', {
  certificate: certDer,
  privateKey: keyDer,
  reason: 'Approved',
  appearance: {                    // optional visible signature
    rect: [50, 50, 200, 80],
    fontSize: 10,
  },
});

const results = await verifySignatures(signed);

import { loadPdf, extractTextWithPositions } from 'modern-pdf-lib';

const doc = await loadPdf(pdfBytes);
const page = doc.getPage(0);
const items = extractTextWithPositions(page.getOperators(), page.getResources());

for (const item of items) {
  console.log(`"${item.text}" at (${item.x}, ${item.y})`);
}

import { loadPdf, initWasm, optimizeAllImages, deduplicateImages } from 'modern-pdf-lib';

await initWasm({ jpeg: true });

const doc = await loadPdf(pdfBytes);

// Deduplicate identical images
const dedupReport = deduplicateImages(doc);

// Optimize all images (JPEG recompression)
const report = await optimizeAllImages(doc, {
  quality: 75,
  progressive: true,
  autoGrayscale: true,
});

console.log(`${report.optimizedImages}/${report.totalImages} images optimized`);
console.log(`Savings: ${report.savings.toFixed(1)}%`);

const optimized = await doc.save();

CLI:

npx modern-pdf optimize report.pdf report-opt.pdf --quality 60 --grayscale --dedup -v

import { createPdf, PageSizes, professionalPreset, applyPreset } from 'modern-pdf-lib';

const doc = createPdf();
const page = doc.addPage(PageSizes.A4);

page.drawTable(applyPreset(professionalPreset(), {
  x: 50,
  y: 750,
  width: 495,
  headerRows: 1,
  rows: [
    { cells: ['Product', 'Qty', 'Price', 'Total'] },
    { cells: ['Widget A', '10', '$5.00', '$50.00'] },
    { cells: ['Widget B', '25', '$3.50', '$87.50'] },
    { cells: [{ content: 'Grand Total', colSpan: 3, align: 'right' }, '$137.50'] },
  ],
  columns: [{ flex: 2 }, { width: 60 }, { width: 80 }, { width: 80, align: 'right' }],
}));

import { createPdf, PageSizes } from 'modern-pdf-lib';

const doc = createPdf();
const page = doc.addPage(PageSizes.A4);

// QR code
page.drawQrCode('https://example.com', { x: 50, y: 700, size: 120 });

// Barcodes (Code 128, EAN-13, UPC-A, Code 39, ITF, PDF417, Data Matrix)
import { encodeCode128, encodeEan13, renderStyledBarcode } from 'modern-pdf-lib';

const barcode = encodeCode128('ABC-12345');
const ops = renderStyledBarcode(barcode, { x: 50, y: 500, height: 60 });

import { enforcePdfA, checkAccessibility } from 'modern-pdf-lib';

// Enforce PDF/A-2b compliance
const archival = enforcePdfA(pdfBytes, '2b');

// Check accessibility
const issues = checkAccessibility(doc);
for (const issue of issues) {
  console.log(`[${issue.severity}] ${issue.code}: ${issue.message}`);
}

Install

# npm
npm install modern-pdf-lib

# pnpm
pnpm add modern-pdf-lib

# yarn
yarn add modern-pdf-lib

# bun
bun add modern-pdf-lib

# deno
import { createPdf } from 'npm:modern-pdf-lib';

WASM Acceleration

All WASM modules are optional. Without them, identical output is produced using pure-JS fallbacks.

import { initWasm } from 'modern-pdf-lib';

await initWasm({
  deflate: true,   // Faster compression
  png: true,       // Faster PNG decoding
  fonts: true,     // Faster font subsetting
  jpeg: true,      // JPEG encode/decode for image optimization
});

| Module | Purpose | Speedup | |:---|:---|:---:| | libdeflate | Stream compression | ~2x | | png | PNG image decoding | ~5x | | ttf | Font parsing & subsetting | ~3x | | shaping | Complex script layout | ~10x | | jbig2 | JBIG2 bilevel image decoding | ~3x | | jpeg | JPEG encode/decode for image optimization | Required |

Project Structure

modern-pdf-lib/
  src/
    core/           PDF document model, objects, writer, pages
    parser/         PDF loading, text extraction, content streams
    form/           AcroForm fields (7 types) + appearances
    annotation/     18 annotation types + appearance generators
    accessibility/  Structure tree, marked content, PDF/UA checker
    compliance/     PDF/A validation & enforcement
    signature/      PKCS#7 signatures, timestamps, verification, CRL/OCSP
    crypto/         AES-256, RC4, MD5, SHA-256/384/512
    compression/    Deflate (fflate + optional WASM)
    assets/         Font metrics/embed/subset, image embed, SVG
    barcode/        QR, Code 128, EAN, UPC, Code 39, ITF, PDF417, Data Matrix
    layout/         Table engine (spanning, pagination, presets, overflow)
    browser/        Download helpers, Service Worker, Web Worker
    layers/         Optional content groups (OCG)
    outline/        Bookmarks / document outline
    metadata/       XMP metadata, viewer preferences
    wasm/           Rust crate sources (6 modules)
    cli/            CLI tool (modern-pdf optimize)
  tests/            4,282 tests across 199 suites
  docs/             VitePress documentation

Contributing

git clone https://github.com/ABCrimson/modern-pdf-lib.git
cd modern-pdf-lib
npm install
npm test          # 4,282 tests
npm run typecheck # TypeScript 6.0 strict
npm run build     # ESM + CJS + declarations

License

MIT © 2026