pdf-lib vs jspdf vs pdfmake
JavaScript 环境下的 PDF 生成与修改方案
pdf-libjspdfpdfmake类似的npm包:

JavaScript 环境下的 PDF 生成与修改方案

jspdf、pdf-lib 和 pdfmake 都是 JavaScript 中处理 PDF 文件的主流库,但它们的侧重点完全不同。jspdf 擅长从头绘制 PDF 内容,采用命令式 API;pdf-lib 专注于修改现有 PDF 文件(如填写表单、合并),同时也支持创建;pdfmake 则使用声明式的 JSON 结构来定义文档,特别适合生成报表和发票。

npm下载趋势

3 年

GitHub Stars 排名

统计详情

npm包名称
下载量
Stars
大小
Issues
发布时间
License
pdf-lib27,588,5568,663-3185 年前MIT
jspdf20,215,29031,31830.2 MB1157 个月前MIT
pdfmake4,102,38512,35912.1 MB2276 天前MIT

jsPDF vs pdf-lib vs pdfmake:架构选型与实战对比

在 JavaScript 生态中处理 PDF 文件时,jspdf、pdf-lib 和 pdfmake 是最常见的三个选择。它们都能生成 PDF,但设计哲学和适用场景差异巨大。本文将从架构角度对比它们的核心机制,帮助你在实际工程中做出正确选择。

🎨 核心设计理念:绘制 vs 修改 vs 声明

jspdf 采用命令式绘制模型。

  • 你像操作画布一样,指定坐标放置文本或线条。
  • 适合从头创建文档,但布局逻辑分散在代码中。
// jspdf: 命令式绘制
import { jsPDF } from "jspdf";
const doc = new jsPDF();
doc.text("Hello World", 10, 10);
doc.save("document.pdf");

pdf-lib 采用对象修改模型。

  • 你操作的是 PDF 文档对象结构,可以创建也可以修改现有文件。
  • 适合处理模板、合并文件或填写表单。
// pdf-lib: 对象操作
import { PDFDocument } from "pdf-lib";
const pdfDoc = await PDFDocument.create();
const page = pdfDoc.addPage();
page.drawText("Hello World", { x: 50, y: 50 });
const pdfBytes = await pdfDoc.save();

pdfmake 采用声明式文档定义。

  • 你描述文档长什么样(JSON 结构),库负责渲染。
  • 适合报表、发票等结构固定的文档。
// pdfmake: 声明式定义
import pdfMake from "pdfmake/build/pdfmake";
const dd = { content: ["Hello World"] };
pdfMake.createPdf(dd).download("document.pdf");

📐 布局与表格:手动坐标 vs 自动流式

处理复杂布局时,三个库的表现截然不同。

jspdf 需要手动计算坐标。

  • 没有内置表格组件,通常需要配合插件(如 autoTable)。
  • 分页逻辑需要自己管理,容易出错。
// jspdf: 手动定位
const doc = new jsPDF();
doc.text("Item", 10, 10);
doc.text("Price", 50, 10);
doc.text("Apple", 10, 20); // 需手动计算 Y 轴

pdf-lib 同样需要手动计算坐标。

  • 它更关注底层 PDF 对象,不提供高级布局工具。
  • 适合精确控制元素位置,不适合长文档流。
// pdf-lib: 手动定位
const page = pdfDoc.addPage();
page.drawText("Item", { x: 10, y: 500 });
page.drawText("Price", { x: 50, y: 500 });
page.drawText("Apple", { x: 10, y: 480 }); // 需手动计算 Y 轴

pdfmake 内置流式布局引擎。

  • 天然支持表格、列布局和多级嵌套。
  • 自动处理分页,无需关心坐标。
// pdfmake: 自动布局
const dd = {
  content: [
    { table: { body: [["Item", "Price"], ["Apple", "10"]] }
  ]
};
pdfMake.createPdf(dd).download();

🔤 字体处理:嵌入 vs 虚拟文件系统

中文支持是前端 PDF 生成的常见痛点。

jspdf 需要手动加载字体文件。

  • 默认不支持中文,需将字体转为 Base64 嵌入。
  • 增加包体积,配置过程繁琐。
// jspdf: 加载自定义字体
doc.addFileToVFS("MyFont.ttf", base64FontString);
doc.addFont("MyFont.ttf", "MyFont", "normal");
doc.setFont("MyFont");

pdf-lib 支持嵌入标准字体或自定义字体。

  • 需要手动读取字体文件并嵌入。
  • 灵活性高,但代码量较大。
// pdf-lib: 嵌入字体
const fontBytes = await fetch("./font.ttf").then(res => res.arrayBuffer());
const customFont = await pdfDoc.embedFont(fontBytes);
page.drawText("你好", { x: 50, y: 50, font: customFont });

pdfmake 使用虚拟文件系统(vfs)。

  • 通常预打包常用字体,或动态加载 vfs_fonts.js。
  • 配置简单,但自定义字体需构建步骤。
// pdfmake: 使用 vfs 字体
// 需预先引入 vfs_fonts.js 包含常用字体
pdfMake.fonts = { Roboto: { /*...*/ } };
const dd = { content: ["文本"], defaultStyle: { font: "Roboto" } };

📝 修改现有 PDF:唯一的选择

如果你需要编辑已有的 PDF 文件,选项非常有限。

jspdf 不支持修改现有 PDF。

  • 只能创建新文件。
  • 无法填写表单或合并页面。
// jspdf: 无法加载现有文件进行修改
// 仅支持 new jsPDF() 创建新文档

pdf-lib 专为修改设计。

  • 可以加载现有字节,修改表单、添加页面或水印。
  • 是此类场景的首选方案。
// pdf-lib: 修改现有文件
const existingPdfBytes = await fetch("./template.pdf").then(res => res.arrayBuffer());
const pdfDoc = await PDFDocument.load(existingPdfBytes);
const form = pdfDoc.getForm();
form.getTextField("name").setText("Alice");

pdfmake 不支持修改现有 PDF。

  • 仅支持从头生成。
  • 适合生成新报告,不适合编辑模板。
// pdfmake: 无法加载现有文件进行修改
// 仅支持 createPdf(dd) 生成新文档

🌱 相似之处:共同的基础能力

尽管差异明显,它们也有一些共同点。

1. 🌐 浏览器与 Node.js 支持

  • 三者均支持在浏览器和 Node.js 环境中运行。
  • 注意文件保存方式不同(下载 vs 文件系统写入)。
// 浏览器:触发下载
doc.save("file.pdf"); // jspdf
pdfBytes => download(pdfBytes); // pdf-lib
pdfMake.createPdf(dd).download(); // pdfmake

// Node.js: 写入文件
fs.writeFileSync("file.pdf", doc.output()); // jspdf
fs.writeFileSync("file.pdf", pdfBytes); // pdf-lib
fs.writeFileSync("file.pdf", result); // pdfmake

2. 🖼️ 图片支持

  • 都支持嵌入图片,但 API 略有不同。
  • 都需要处理图片数据(Base64 或 ArrayBuffer)。
// jspdf
doc.addImgData(imgData, "JPEG", 10, 10, 100, 100);

// pdf-lib
const jpgBytes = await fetch("./img.jpg").then(res => res.arrayBuffer());
const jpgImage = await pdfDoc.embedJpg(jpgBytes);
page.drawImage(jpgImage, { x: 50, y: 50, width: 100, height: 100 });

// pdfmake
const dd = { content: [{ image: "data:image/jpeg;base64,...", width: 100 }] };

3. 🔒 纯前端处理

  • 都不需要后端服务参与生成过程。
  • 适合隐私敏感数据或离线场景。
// 三者均可直接在浏览器运行,无需服务器
// 数据不出客户端,安全性较高

📊 总结对比表

特性jspdfpdf-libpdfmake
核心用途从头创建简单 PDF修改现有 PDF / 创建生成复杂报表
布局方式命令式坐标命令式坐标声明式 JSON
表格支持需插件 (autoTable)手动绘制内置支持
修改现有文件❌ 不支持✅ 支持❌ 不支持
字体配置Base64 嵌入手动嵌入VFS 预加载
学习曲线低中低

💡 架构师建议

jspdf 像是一把通用螺丝刀 🔧——适合快速解决简单问题,社区资源多,但处理复杂任务时效率低。适合内部工具、简单凭证生成。

pdf-lib 像是一把手术刀 🪓——精准控制 PDF 结构,适合需要编辑、合并或填写表单的场景。适合合同系统、文档处理流水线。

pdfmake 像是一个排版引擎 📄——专注于文档内容结构,适合生成发票、报表等固定格式文档。适合数据报告、导出功能。

最终建议:不要试图用一个库解决所有问题。如果需要修改现有文件,必须选 pdf-lib。如果需要生成复杂表格报表,pdfmake 效率最高。如果只是简单导出文本或图片,jspdf 足够轻量。根据具体业务场景组合使用,往往能获得最佳效果。

如何选择: pdf-lib vs jspdf vs pdfmake

  • pdf-lib:

    选择 pdf-lib 如果你的核心需求是修改现有的 PDF 模板,例如填写表单、合并文件或添加水印。它在处理现有文档结构方面表现最好,也支持从头创建,但布局需要手动计算坐标。

  • jspdf:

    选择 jspdf 如果你需要快速从头生成简单的 PDF 文件,且不需要复杂的表格布局。它适合简单的文本和图片拼接场景,社区插件丰富,但处理复杂排版时代码会变得繁琐。

  • pdfmake:

    选择 pdfmake 如果你需要生成结构复杂的报表、发票或包含表格的文档。它的声明式配置让布局管理更简单,内置了对表格和列的良好支持,但自定义绘图能力较弱。

pdf-lib的README

pdf-lib

Create and modify PDF documents in any JavaScript environment.
Designed to work in any modern JavaScript runtime. Tested in Node, Browser, Deno, and React Native environments.


Learn more at pdf-lib.js.org

Table of Contents

Features

  • Create new PDFs
  • Modify existing PDFs
  • Create forms
  • Fill forms
  • Flatten forms
  • Add Pages
  • Insert Pages
  • Remove Pages
  • Copy pages between PDFs
  • Draw Text
  • Draw Images
  • Draw PDF Pages
  • Draw Vector Graphics
  • Draw SVG Paths
  • Measure width and height of text
  • Embed Fonts (supports UTF-8 and UTF-16 character sets)
  • Set document metadata
  • Read document metadata
  • Set viewer preferences
  • Read viewer preferences
  • Add attachments

Motivation

pdf-lib was created to address the JavaScript ecosystem's lack of robust support for PDF manipulation (especially for PDF modification).

Two of pdf-lib's distinguishing features are:

  1. Supporting modification (editing) of existing documents.
  2. Working in all JavaScript environments - not just in Node or the Browser.

There are other good open source JavaScript PDF libraries available. However, most of them can only create documents, they cannot modify existing ones. And many of them only work in particular environments.

Usage Examples

Create Document

This example produces this PDF.

Try the JSFiddle demo

import { PDFDocument, StandardFonts, rgb } from 'pdf-lib'

// Create a new PDFDocument
const pdfDoc = await PDFDocument.create()

// Embed the Times Roman font
const timesRomanFont = await pdfDoc.embedFont(StandardFonts.TimesRoman)

// Add a blank page to the document
const page = pdfDoc.addPage()

// Get the width and height of the page
const { width, height } = page.getSize()

// Draw a string of text toward the top of the page
const fontSize = 30
page.drawText('Creating PDFs in JavaScript is awesome!', {
  x: 50,
  y: height - 4 * fontSize,
  size: fontSize,
  font: timesRomanFont,
  color: rgb(0, 0.53, 0.71),
})

// Serialize the PDFDocument to bytes (a Uint8Array)
const pdfBytes = await pdfDoc.save()

// For example, `pdfBytes` can be:
//   • Written to a file in Node
//   • Downloaded from the browser
//   • Rendered in an <iframe>

Modify Document

This example produces this PDF (when this PDF is used for the existingPdfBytes variable).

Try the JSFiddle demo

import { degrees, PDFDocument, rgb, StandardFonts } from 'pdf-lib';

// This should be a Uint8Array or ArrayBuffer
// This data can be obtained in a number of different ways
// If your running in a Node environment, you could use fs.readFile()
// In the browser, you could make a fetch() call and use res.arrayBuffer()
const existingPdfBytes = ...

// Load a PDFDocument from the existing PDF bytes
const pdfDoc = await PDFDocument.load(existingPdfBytes)

// Embed the Helvetica font
const helveticaFont = await pdfDoc.embedFont(StandardFonts.Helvetica)

// Get the first page of the document
const pages = pdfDoc.getPages()
const firstPage = pages[0]

// Get the width and height of the first page
const { width, height } = firstPage.getSize()

// Draw a string of text diagonally across the first page
firstPage.drawText('This text was added with JavaScript!', {
  x: 5,
  y: height / 2 + 300,
  size: 50,
  font: helveticaFont,
  color: rgb(0.95, 0.1, 0.1),
  rotate: degrees(-45),
})


// Serialize the PDFDocument to bytes (a Uint8Array)
const pdfBytes = await pdfDoc.save()

// For example, `pdfBytes` can be:
//   • Written to a file in Node
//   • Downloaded from the browser
//   • Rendered in an <iframe>

Create Form

This example produces this PDF.

Try the JSFiddle demo

See also Creating and Filling Forms

import { PDFDocument } from 'pdf-lib'

// Create a new PDFDocument
const pdfDoc = await PDFDocument.create()

// Add a blank page to the document
const page = pdfDoc.addPage([550, 750])

// Get the form so we can add fields to it
const form = pdfDoc.getForm()

// Add the superhero text field and description
page.drawText('Enter your favorite superhero:', { x: 50, y: 700, size: 20 })

const superheroField = form.createTextField('favorite.superhero')
superheroField.setText('One Punch Man')
superheroField.addToPage(page, { x: 55, y: 640 })

// Add the rocket radio group, labels, and description
page.drawText('Select your favorite rocket:', { x: 50, y: 600, size: 20 })

page.drawText('Falcon Heavy', { x: 120, y: 560, size: 18 })
page.drawText('Saturn IV', { x: 120, y: 500, size: 18 })
page.drawText('Delta IV Heavy', { x: 340, y: 560, size: 18 })
page.drawText('Space Launch System', { x: 340, y: 500, size: 18 })

const rocketField = form.createRadioGroup('favorite.rocket')
rocketField.addOptionToPage('Falcon Heavy', page, { x: 55, y: 540 })
rocketField.addOptionToPage('Saturn IV', page, { x: 55, y: 480 })
rocketField.addOptionToPage('Delta IV Heavy', page, { x: 275, y: 540 })
rocketField.addOptionToPage('Space Launch System', page, { x: 275, y: 480 })
rocketField.select('Saturn IV')

// Add the gundam check boxes, labels, and description
page.drawText('Select your favorite gundams:', { x: 50, y: 440, size: 20 })

page.drawText('Exia', { x: 120, y: 400, size: 18 })
page.drawText('Kyrios', { x: 120, y: 340, size: 18 })
page.drawText('Virtue', { x: 340, y: 400, size: 18 })
page.drawText('Dynames', { x: 340, y: 340, size: 18 })

const exiaField = form.createCheckBox('gundam.exia')
const kyriosField = form.createCheckBox('gundam.kyrios')
const virtueField = form.createCheckBox('gundam.virtue')
const dynamesField = form.createCheckBox('gundam.dynames')

exiaField.addToPage(page, { x: 55, y: 380 })
kyriosField.addToPage(page, { x: 55, y: 320 })
virtueField.addToPage(page, { x: 275, y: 380 })
dynamesField.addToPage(page, { x: 275, y: 320 })

exiaField.check()
dynamesField.check()

// Add the planet dropdown and description
page.drawText('Select your favorite planet*:', { x: 50, y: 280, size: 20 })

const planetsField = form.createDropdown('favorite.planet')
planetsField.addOptions(['Venus', 'Earth', 'Mars', 'Pluto'])
planetsField.select('Pluto')
planetsField.addToPage(page, { x: 55, y: 220 })

// Add the person option list and description
page.drawText('Select your favorite person:', { x: 50, y: 180, size: 18 })

const personField = form.createOptionList('favorite.person')
personField.addOptions([
  'Julius Caesar',
  'Ada Lovelace',
  'Cleopatra',
  'Aaron Burr',
  'Mark Antony',
])
personField.select('Ada Lovelace')
personField.addToPage(page, { x: 55, y: 70 })

// Just saying...
page.drawText(`* Pluto should be a planet too!`, { x: 15, y: 15, size: 15 })

// Serialize the PDFDocument to bytes (a Uint8Array)
const pdfBytes = await pdfDoc.save()

// For example, `pdfBytes` can be:
//   • Written to a file in Node
//   • Downloaded from the browser
//   • Rendered in an <iframe>

Fill Form

This example produces this PDF (when this PDF is used for the formPdfBytes variable, this image is used for the marioImageBytes variable, and this image is used for the emblemImageBytes variable).

Try the JSFiddle demo

See also Creating and Filling Forms

import { PDFDocument } from 'pdf-lib'

// These should be Uint8Arrays or ArrayBuffers
// This data can be obtained in a number of different ways
// If your running in a Node environment, you could use fs.readFile()
// In the browser, you could make a fetch() call and use res.arrayBuffer()
const formPdfBytes = ...
const marioImageBytes = ...
const emblemImageBytes = ...

// Load a PDF with form fields
const pdfDoc = await PDFDocument.load(formPdfBytes)

// Embed the Mario and emblem images
const marioImage = await pdfDoc.embedPng(marioImageBytes)
const emblemImage = await pdfDoc.embedPng(emblemImageBytes)

// Get the form containing all the fields
const form = pdfDoc.getForm()

// Get all fields in the PDF by their names
const nameField = form.getTextField('CharacterName 2')
const ageField = form.getTextField('Age')
const heightField = form.getTextField('Height')
const weightField = form.getTextField('Weight')
const eyesField = form.getTextField('Eyes')
const skinField = form.getTextField('Skin')
const hairField = form.getTextField('Hair')

const alliesField = form.getTextField('Allies')
const factionField = form.getTextField('FactionName')
const backstoryField = form.getTextField('Backstory')
const traitsField = form.getTextField('Feat+Traits')
const treasureField = form.getTextField('Treasure')

const characterImageField = form.getButton('CHARACTER IMAGE')
const factionImageField = form.getTextField('Faction Symbol Image')

// Fill in the basic info fields
nameField.setText('Mario')
ageField.setText('24 years')
heightField.setText(`5' 1"`)
weightField.setText('196 lbs')
eyesField.setText('blue')
skinField.setText('white')
hairField.setText('brown')

// Fill the character image field with our Mario image
characterImageField.setImage(marioImage)

// Fill in the allies field
alliesField.setText(
  [
    `Allies:`,
    `  • Princess Daisy`,
    `  • Princess Peach`,
    `  • Rosalina`,
    `  • Geno`,
    `  • Luigi`,
    `  • Donkey Kong`,
    `  • Yoshi`,
    `  • Diddy Kong`,
    ``,
    `Organizations:`,
    `  • Italian Plumbers Association`,
  ].join('\n'),
)

// Fill in the faction name field
factionField.setText(`Mario's Emblem`)

// Fill the faction image field with our emblem image
factionImageField.setImage(emblemImage)

// Fill in the backstory field
backstoryField.setText(
  `Mario is a fictional character in the Mario video game franchise, owned by Nintendo and created by Japanese video game designer Shigeru Miyamoto. Serving as the company's mascot and the eponymous protagonist of the series, Mario has appeared in over 200 video games since his creation. Depicted as a short, pudgy, Italian plumber who resides in the Mushroom Kingdom, his adventures generally center upon rescuing Princess Peach from the Koopa villain Bowser. His younger brother and sidekick is Luigi.`,
)

// Fill in the traits field
traitsField.setText(
  [
    `Mario can use three basic three power-ups:`,
    `  • the Super Mushroom, which causes Mario to grow larger`,
    `  • the Fire Flower, which allows Mario to throw fireballs`,
    `  • the Starman, which gives Mario temporary invincibility`,
  ].join('\n'),
)

// Fill in the treasure field
treasureField.setText(['• Gold coins', '• Treasure chests'].join('\n'))

// Serialize the PDFDocument to bytes (a Uint8Array)
const pdfBytes = await pdfDoc.save()

// For example, `pdfBytes` can be:
//   • Written to a file in Node
//   • Downloaded from the browser
//   • Rendered in an <iframe>

Flatten Form

This example produces this PDF (when this PDF is used for the formPdfBytes variable).

Try the JSFiddle demo

import { PDFDocument } from 'pdf-lib'

// This should be a Uint8Array or ArrayBuffer
// This data can be obtained in a number of different ways
// If your running in a Node environment, you could use fs.readFile()
// In the browser, you could make a fetch() call and use res.arrayBuffer()
const formPdfBytes = ...

// Load a PDF with form fields
const pdfDoc = await PDFDocument.load(formPdfBytes)

// Get the form containing all the fields
const form = pdfDoc.getForm()

// Fill the form's fields
form.getTextField('Text1').setText('Some Text');

form.getRadioGroup('Group2').select('Choice1');
form.getRadioGroup('Group3').select('Choice3');
form.getRadioGroup('Group4').select('Choice1');

form.getCheckBox('Check Box3').check();
form.getCheckBox('Check Box4').uncheck();

form.getDropdown('Dropdown7').select('Infinity');

form.getOptionList('List Box6').select('Honda');

// Flatten the form's fields
form.flatten();

// Serialize the PDFDocument to bytes (a Uint8Array)
const pdfBytes = await pdfDoc.save()

// For example, `pdfBytes` can be:
//   • Written to a file in Node
//   • Downloaded from the browser
//   • Rendered in an <iframe>

Copy Pages

This example produces this PDF (when this PDF is used for the firstDonorPdfBytes variable and this PDF is used for the secondDonorPdfBytes variable).

Try the JSFiddle demo

import { PDFDocument } from 'pdf-lib'

// Create a new PDFDocument
const pdfDoc = await PDFDocument.create()

// These should be Uint8Arrays or ArrayBuffers
// This data can be obtained in a number of different ways
// If your running in a Node environment, you could use fs.readFile()
// In the browser, you could make a fetch() call and use res.arrayBuffer()
const firstDonorPdfBytes = ...
const secondDonorPdfBytes = ...

// Load a PDFDocument from each of the existing PDFs
const firstDonorPdfDoc = await PDFDocument.load(firstDonorPdfBytes)
const secondDonorPdfDoc = await PDFDocument.load(secondDonorPdfBytes)

// Copy the 1st page from the first donor document, and
// the 743rd page from the second donor document
const [firstDonorPage] = await pdfDoc.copyPages(firstDonorPdfDoc, [0])
const [secondDonorPage] = await pdfDoc.copyPages(secondDonorPdfDoc, [742])

// Add the first copied page
pdfDoc.addPage(firstDonorPage)

// Insert the second copied page to index 0, so it will be the
// first page in `pdfDoc`
pdfDoc.insertPage(0, secondDonorPage)

// Serialize the PDFDocument to bytes (a Uint8Array)
const pdfBytes = await pdfDoc.save()

// For example, `pdfBytes` can be:
//   • Written to a file in Node
//   • Downloaded from the browser
//   • Rendered in an <iframe>

Embed PNG and JPEG Images

This example produces this PDF (when this image is used for the jpgImageBytes variable and this image is used for the pngImageBytes variable).

Try the JSFiddle demo

import { PDFDocument } from 'pdf-lib'

// These should be Uint8Arrays or ArrayBuffers
// This data can be obtained in a number of different ways
// If your running in a Node environment, you could use fs.readFile()
// In the browser, you could make a fetch() call and use res.arrayBuffer()
const jpgImageBytes = ...
const pngImageBytes = ...

// Create a new PDFDocument
const pdfDoc = await PDFDocument.create()

// Embed the JPG image bytes and PNG image bytes
const jpgImage = await pdfDoc.embedJpg(jpgImageBytes)
const pngImage = await pdfDoc.embedPng(pngImageBytes)

// Get the width/height of the JPG image scaled down to 25% of its original size
const jpgDims = jpgImage.scale(0.25)

// Get the width/height of the PNG image scaled down to 50% of its original size
const pngDims = pngImage.scale(0.5)

// Add a blank page to the document
const page = pdfDoc.addPage()

// Draw the JPG image in the center of the page
page.drawImage(jpgImage, {
  x: page.getWidth() / 2 - jpgDims.width / 2,
  y: page.getHeight() / 2 - jpgDims.height / 2,
  width: jpgDims.width,
  height: jpgDims.height,
})

// Draw the PNG image near the lower right corner of the JPG image
page.drawImage(pngImage, {
  x: page.getWidth() / 2 - pngDims.width / 2 + 75,
  y: page.getHeight() / 2 - pngDims.height,
  width: pngDims.width,
  height: pngDims.height,
})

// Serialize the PDFDocument to bytes (a Uint8Array)
const pdfBytes = await pdfDoc.save()

// For example, `pdfBytes` can be:
//   • Written to a file in Node
//   • Downloaded from the browser
//   • Rendered in an <iframe>

Embed PDF Pages

This example produces this PDF (when this PDF is used for the americanFlagPdfBytes variable and this PDF is used for the usConstitutionPdfBytes variable).

Try the JSFiddle demo

import { PDFDocument } from 'pdf-lib'

// These should be Uint8Arrays or ArrayBuffers
// This data can be obtained in a number of different ways
// If your running in a Node environment, you could use fs.readFile()
// In the browser, you could make a fetch() call and use res.arrayBuffer()
const americanFlagPdfBytes = ...
const usConstitutionPdfBytes = ...

// Create a new PDFDocument
const pdfDoc = await PDFDocument.create()

// Embed the American flag PDF bytes
const [americanFlag] = await pdfDoc.embedPdf(americanFlagPdfBytes)

// Load the U.S. constitution PDF bytes
const usConstitutionPdf = await PDFDocument.load(usConstitutionPdfBytes)

// Embed the second page of the constitution and clip the preamble
const preamble = await pdfDoc.embedPage(usConstitutionPdf.getPages()[1], {
  left: 55,
  bottom: 485,
  right: 300,
  top: 575,
})

// Get the width/height of the American flag PDF scaled down to 30% of
// its original size
const americanFlagDims = americanFlag.scale(0.3)

// Get the width/height of the preamble clipping scaled up to 225% of
// its original size
const preambleDims = preamble.scale(2.25)

// Add a blank page to the document
const page = pdfDoc.addPage()

// Draw the American flag image in the center top of the page
page.drawPage(americanFlag, {
  ...americanFlagDims,
  x: page.getWidth() / 2 - americanFlagDims.width / 2,
  y: page.getHeight() - americanFlagDims.height - 150,
})

// Draw the preamble clipping in the center bottom of the page
page.drawPage(preamble, {
  ...preambleDims,
  x: page.getWidth() / 2 - preambleDims.width / 2,
  y: page.getHeight() / 2 - preambleDims.height / 2 - 50,
})

// Serialize the PDFDocument to bytes (a Uint8Array)
const pdfBytes = await pdfDoc.save()

// For example, `pdfBytes` can be:
//   • Written to a file in Node
//   • Downloaded from the browser
//   • Rendered in an <iframe>

Embed Font and Measure Text

pdf-lib relies on a sister module to support embedding custom fonts: @pdf-lib/fontkit. You must add the @pdf-lib/fontkit module to your project and register it using pdfDoc.registerFontkit(...) before embedding custom fonts.

See below for detailed installation instructions on installing @pdf-lib/fontkit as a UMD or NPM module.

This example produces this PDF (when this font is used for the fontBytes variable).

Try the JSFiddle demo

import { PDFDocument, rgb } from 'pdf-lib'
import fontkit from '@pdf-lib/fontkit'

// This should be a Uint8Array or ArrayBuffer
// This data can be obtained in a number of different ways
// If you're running in a Node environment, you could use fs.readFile()
// In the browser, you could make a fetch() call and use res.arrayBuffer()
const fontBytes = ...

// Create a new PDFDocument
const pdfDoc = await PDFDocument.create()

// Register the `fontkit` instance
pdfDoc.registerFontkit(fontkit)

// Embed our custom font in the document
const customFont = await pdfDoc.embedFont(fontBytes)

// Add a blank page to the document
const page = pdfDoc.addPage()

// Create a string of text and measure its width and height in our custom font
const text = 'This is text in an embedded font!'
const textSize = 35
const textWidth = customFont.widthOfTextAtSize(text, textSize)
const textHeight = customFont.heightAtSize(textSize)

// Draw the string of text on the page
page.drawText(text, {
  x: 40,
  y: 450,
  size: textSize,
  font: customFont,
  color: rgb(0, 0.53, 0.71),
})

// Draw a box around the string of text
page.drawRectangle({
  x: 40,
  y: 450,
  width: textWidth,
  height: textHeight,
  borderColor: rgb(1, 0, 0),
  borderWidth: 1.5,
})

// Serialize the PDFDocument to bytes (a Uint8Array)
const pdfBytes = await pdfDoc.save()

// For example, `pdfBytes` can be:
//   • Written to a file in Node
//   • Downloaded from the browser
//   • Rendered in an <iframe>

Add Attachments

This example produces this PDF (when this image is used for the jpgAttachmentBytes variable and this PDF is used for the pdfAttachmentBytes variable).

Try the JSFiddle demo

import { PDFDocument } from 'pdf-lib'

// These should be Uint8Arrays or ArrayBuffers
// This data can be obtained in a number of different ways
// If your running in a Node environment, you could use fs.readFile()
// In the browser, you could make a fetch() call and use res.arrayBuffer()
const jpgAttachmentBytes = ...
const pdfAttachmentBytes = ...

// Create a new PDFDocument
const pdfDoc = await PDFDocument.create()

// Add the JPG attachment
await pdfDoc.attach(jpgAttachmentBytes, 'cat_riding_unicorn.jpg', {
  mimeType: 'image/jpeg',
  description: 'Cool cat riding a unicorn! 🦄🐈🕶️',
  creationDate: new Date('2019/12/01'),
  modificationDate: new Date('2020/04/19'),
})

// Add the PDF attachment
await pdfDoc.attach(pdfAttachmentBytes, 'us_constitution.pdf', {
  mimeType: 'application/pdf',
  description: 'Constitution of the United States 🇺🇸🦅',
  creationDate: new Date('1787/09/17'),
  modificationDate: new Date('1992/05/07'),
})

// Add a page with some text
const page = pdfDoc.addPage();
page.drawText('This PDF has two attachments', { x: 135, y: 415 })

// Serialize the PDFDocument to bytes (a Uint8Array)
const pdfBytes = await pdfDoc.save()

// For example, `pdfBytes` can be:
//   • Written to a file in Node
//   • Downloaded from the browser
//   • Rendered in an <iframe>

Set Document Metadata

This example produces this PDF.

Try the JSFiddle demo

import { PDFDocument, StandardFonts } from 'pdf-lib'

// Create a new PDFDocument
const pdfDoc = await PDFDocument.create()

// Embed the Times Roman font
const timesRomanFont = await pdfDoc.embedFont(StandardFonts.TimesRoman)

// Add a page and draw some text on it
const page = pdfDoc.addPage([500, 600])
page.setFont(timesRomanFont)
page.drawText('The Life of an Egg', { x: 60, y: 500, size: 50 })
page.drawText('An Epic Tale of Woe', { x: 125, y: 460, size: 25 })

// Set all available metadata fields on the PDFDocument. Note that these fields
// are visible in the "Document Properties" section of most PDF readers.
pdfDoc.setTitle('🥚 The Life of an Egg 🍳')
pdfDoc.setAuthor('Humpty Dumpty')
pdfDoc.setSubject('📘 An Epic Tale of Woe 📖')
pdfDoc.setKeywords(['eggs', 'wall', 'fall', 'king', 'horses', 'men'])
pdfDoc.setProducer('PDF App 9000 🤖')
pdfDoc.setCreator('pdf-lib (https://github.com/Hopding/pdf-lib)')
pdfDoc.setCreationDate(new Date('2018-06-24T01:58:37.228Z'))
pdfDoc.setModificationDate(new Date('2019-12-21T07:00:11.000Z'))

// Serialize the PDFDocument to bytes (a Uint8Array)
const pdfBytes = await pdfDoc.save()

// For example, `pdfBytes` can be:
//   • Written to a file in Node
//   • Downloaded from the browser
//   • Rendered in an <iframe>

Read Document Metadata

Try the JSFiddle demo

import { PDFDocument } from 'pdf-lib'

// This should be a Uint8Array or ArrayBuffer
// This data can be obtained in a number of different ways
// If your running in a Node environment, you could use fs.readFile()
// In the browser, you could make a fetch() call and use res.arrayBuffer()
const existingPdfBytes = ...

// Load a PDFDocument without updating its existing metadata
const pdfDoc = await PDFDocument.load(existingPdfBytes, {
  updateMetadata: false
})

// Print all available metadata fields
console.log('Title:', pdfDoc.getTitle())
console.log('Author:', pdfDoc.getAuthor())
console.log('Subject:', pdfDoc.getSubject())
console.log('Creator:', pdfDoc.getCreator())
console.log('Keywords:', pdfDoc.getKeywords())
console.log('Producer:', pdfDoc.getProducer())
console.log('Creation Date:', pdfDoc.getCreationDate())
console.log('Modification Date:', pdfDoc.getModificationDate())

This script outputs the following (when this PDF is used for the existingPdfBytes variable):

Title: Microsoft Word - Basic Curriculum Vitae example.doc
Author: Administrator
Subject: undefined
Creator: PScript5.dll Version 5.2
Keywords: undefined
Producer: Acrobat Distiller 8.1.0 (Windows)
Creation Date: 2010-07-29T14:26:00.000Z
Modification Date: 2010-07-29T14:26:00.000Z

Set Viewer Preferences

import {
  PDFDocument,
  StandardFonts,
  NonFullScreenPageMode,
  ReadingDirection,
  PrintScaling,
  Duplex,
  PDFName,
} from 'pdf-lib'

// Create a new PDFDocument
const pdfDoc = await PDFDocument.create()

// Embed the Times Roman font
const timesRomanFont = await pdfDoc.embedFont(StandardFonts.TimesRoman)

// Add a page and draw some text on it
const page = pdfDoc.addPage([500, 600])
page.setFont(timesRomanFont)
page.drawText('The Life of an Egg', { x: 60, y: 500, size: 50 })
page.drawText('An Epic Tale of Woe', { x: 125, y: 460, size: 25 })

// Set all available viewer preferences on the PDFDocument:
const viewerPrefs = pdfDoc.catalog.getOrCreateViewerPreferences()
viewerPrefs.setHideToolbar(true)
viewerPrefs.setHideMenubar(true)
viewerPrefs.setHideWindowUI(true)
viewerPrefs.setFitWindow(true)
viewerPrefs.setCenterWindow(true)
viewerPrefs.setDisplayDocTitle(true)

// Set the PageMode (otherwise setting NonFullScreenPageMode has no meaning)
pdfDoc.catalog.set(PDFName.of('PageMode'), PDFName.of('FullScreen'))

// Set what happens when fullScreen is closed
viewerPrefs.setNonFullScreenPageMode(NonFullScreenPageMode.UseOutlines)

viewerPrefs.setReadingDirection(ReadingDirection.L2R)
viewerPrefs.setPrintScaling(PrintScaling.None)
viewerPrefs.setDuplex(Duplex.DuplexFlipLongEdge)
viewerPrefs.setPickTrayByPDFSize(true)

// We can set the default print range to only the first page
viewerPrefs.setPrintPageRange({ start: 0, end: 0 })

// Or we can supply noncontiguous ranges (e.g. pages 1, 3, and 5-7)
viewerPrefs.setPrintPageRange([
  { start: 0, end: 0 },
  { start: 2, end: 2 },
  { start: 4, end: 6 },
])

viewerPrefs.setNumCopies(2)

// Serialize the PDFDocument to bytes (a Uint8Array)
const pdfBytes = await pdfDoc.save()

// For example, `pdfBytes` can be:
//   • Written to a file in Node
//   • Downloaded from the browser
//   • Rendered in an <iframe>

Read Viewer Preferences

import { PDFDocument } from 'pdf-lib'

// This should be a Uint8Array or ArrayBuffer
// This data can be obtained in a number of different ways
// If your running in a Node environment, you could use fs.readFile()
// In the browser, you could make a fetch() call and use res.arrayBuffer()
const existingPdfBytes = ...

// Load a PDFDocument without updating its existing metadata
const pdfDoc = await PDFDocument.load(existingPdfBytes)
const viewerPrefs = pdfDoc.catalog.getOrCreateViewerPreferences()

// Print all available viewer preference fields
console.log('HideToolbar:', viewerPrefs.getHideToolbar())
console.log('HideMenubar:', viewerPrefs.getHideMenubar())
console.log('HideWindowUI:', viewerPrefs.getHideWindowUI())
console.log('FitWindow:', viewerPrefs.getFitWindow())
console.log('CenterWindow:', viewerPrefs.getCenterWindow())
console.log('DisplayDocTitle:', viewerPrefs.getDisplayDocTitle())
console.log('NonFullScreenPageMode:', viewerPrefs.getNonFullScreenPageMode())
console.log('ReadingDirection:', viewerPrefs.getReadingDirection())
console.log('PrintScaling:', viewerPrefs.getPrintScaling())
console.log('Duplex:', viewerPrefs.getDuplex())
console.log('PickTrayByPDFSize:', viewerPrefs.getPickTrayByPDFSize())
console.log('PrintPageRange:', viewerPrefs.getPrintPageRange())
console.log('NumCopies:', viewerPrefs.getNumCopies())

This script outputs the following (when this PDF is used for the existingPdfBytes variable):

HideToolbar: true
HideMenubar: true
HideWindowUI: false
FitWindow: true
CenterWindow: true
DisplayDocTitle: true
NonFullScreenPageMode: UseNone
ReadingDirection: R2L
PrintScaling: None
Duplex: DuplexFlipLongEdge
PickTrayByPDFSize: true
PrintPageRange: [ { start: 1, end: 1 }, { start: 3, end: 4 } ]
NumCopies: 2

Draw SVG Paths

This example produces this PDF.

Try the JSFiddle demo

import { PDFDocument, rgb } from 'pdf-lib'

// SVG path for a wavy line
const svgPath =
  'M 0,20 L 100,160 Q 130,200 150,120 C 190,-40 200,200 300,150 L 400,90'

// Create a new PDFDocument
const pdfDoc = await PDFDocument.create()

// Add a blank page to the document
const page = pdfDoc.addPage()
page.moveTo(100, page.getHeight() - 5)

// Draw the SVG path as a black line
page.moveDown(25)
page.drawSvgPath(svgPath)

// Draw the SVG path as a thick green line
page.moveDown(200)
page.drawSvgPath(svgPath, { borderColor: rgb(0, 1, 0), borderWidth: 5 })

// Draw the SVG path and fill it with red
page.moveDown(200)
page.drawSvgPath(svgPath, { color: rgb(1, 0, 0) })

// Draw the SVG path at 50% of its original size
page.moveDown(200)
page.drawSvgPath(svgPath, { scale: 0.5 })

// Serialize the PDFDocument to bytes (a Uint8Array)
const pdfBytes = await pdfDoc.save()

// For example, `pdfBytes` can be:
//   • Written to a file in Node
//   • Downloaded from the browser
//   • Rendered in an <iframe>

Deno Usage

pdf-lib fully supports the exciting new Deno runtime! All of the usage examples work in Deno. The only thing you need to do is change the imports for pdf-lib and @pdf-lib/fontkit to use the Skypack CDN, because Deno requires all modules to be referenced via URLs.

See also How to Create and Modify PDF Files in Deno With pdf-lib

Creating a Document with Deno

Below is the create document example modified for Deno:

import {
  PDFDocument,
  StandardFonts,
  rgb,
} from 'https://cdn.skypack.dev/pdf-lib@^1.11.1?dts';

const pdfDoc = await PDFDocument.create();
const timesRomanFont = await pdfDoc.embedFont(StandardFonts.TimesRoman);

const page = pdfDoc.addPage();
const { width, height } = page.getSize();
const fontSize = 30;
page.drawText('Creating PDFs in JavaScript is awesome!', {
  x: 50,
  y: height - 4 * fontSize,
  size: fontSize,
  font: timesRomanFont,
  color: rgb(0, 0.53, 0.71),
});

const pdfBytes = await pdfDoc.save();

await Deno.writeFile('out.pdf', pdfBytes);

If you save this script as create-document.ts, you can execute it using Deno with the following command:

deno run --allow-write create-document.ts

The resulting out.pdf file will look like this PDF.

Embedding a Font with Deno

Here's a slightly more complicated example demonstrating how to embed a font and measure text in Deno:

import {
  degrees,
  PDFDocument,
  rgb,
  StandardFonts,
} from 'https://cdn.skypack.dev/pdf-lib@^1.11.1?dts';
import fontkit from 'https://cdn.skypack.dev/@pdf-lib/fontkit@^1.0.0?dts';

const url = 'https://pdf-lib.js.org/assets/ubuntu/Ubuntu-R.ttf';
const fontBytes = await fetch(url).then((res) => res.arrayBuffer());

const pdfDoc = await PDFDocument.create();

pdfDoc.registerFontkit(fontkit);
const customFont = await pdfDoc.embedFont(fontBytes);

const page = pdfDoc.addPage();

const text = 'This is text in an embedded font!';
const textSize = 35;
const textWidth = customFont.widthOfTextAtSize(text, textSize);
const textHeight = customFont.heightAtSize(textSize);

page.drawText(text, {
  x: 40,
  y: 450,
  size: textSize,
  font: customFont,
  color: rgb(0, 0.53, 0.71),
});
page.drawRectangle({
  x: 40,
  y: 450,
  width: textWidth,
  height: textHeight,
  borderColor: rgb(1, 0, 0),
  borderWidth: 1.5,
});

const pdfBytes = await pdfDoc.save();

await Deno.writeFile('out.pdf', pdfBytes);

If you save this script as custom-font.ts, you can execute it with the following command:

deno run --allow-write --allow-net custom-font.ts

The resulting out.pdf file will look like this PDF.

Complete Examples

The usage examples provide code that is brief and to the point, demonstrating the different features of pdf-lib. You can find complete working examples in the apps/ directory. These apps are used to do manual testing of pdf-lib before every release (in addition to the automated tests).

There are currently four apps:

  • node - contains tests for pdf-lib in Node environments. These tests are a handy reference when trying to save/load PDFs, fonts, or images with pdf-lib from the filesystem. They also allow you to quickly open your PDFs in different viewers (Acrobat, Preview, Foxit, Chrome, Firefox, etc...) to ensure compatibility.
  • web - contains tests for pdf-lib in browser environments. These tests are a handy reference when trying to save/load PDFs, fonts, or images with pdf-lib in a browser environment.
  • rn - contains tests for pdf-lib in React Native environments. These tests are a handy reference when trying to save/load PDFs, fonts, or images with pdf-lib in a React Native environment.
  • deno - contains tests for pdf-lib in Deno environments. These tests are a handy reference when trying to save/load PDFs, fonts, or images with pdf-lib from the filesystem.

Installation

NPM Module

To install the latest stable version:

# With npm
npm install --save pdf-lib

# With yarn
yarn add pdf-lib

This assumes you're using npm or yarn as your package manager.

UMD Module

You can also download pdf-lib as a UMD module from unpkg or jsDelivr. The UMD builds have been compiled to ES5, so they should work in any modern browser. UMD builds are useful if you aren't using a package manager or module bundler. For example, you can use them directly in the <script> tag of an HTML page.

The following builds are available:

NOTE: if you are using the CDN scripts in production, you should include a specific version number in the URL, for example:

When using a UMD build, you will have access to a global window.PDFLib variable. This variable contains all of the classes and functions exported by pdf-lib. For example:

// NPM module
import { PDFDocument, rgb } from 'pdf-lib';

// UMD module
var PDFDocument = PDFLib.PDFDocument;
var rgb = PDFLib.rgb;

Fontkit Installation

pdf-lib relies upon a sister module to support embedding custom fonts: @pdf-lib/fontkit. You must add the @pdf-lib/fontkit module to your project and register it using pdfDoc.registerFontkit(...) before embedding custom fonts (see the font embedding example). This module is not included by default because not all users need it, and it increases bundle size.

Installing this module is easy. Just like pdf-lib itself, @pdf-lib/fontkit can be installed with npm/yarn or as a UMD module.

Fontkit NPM Module

# With npm
npm install --save @pdf-lib/fontkit

# With yarn
yarn add @pdf-lib/fontkit

To register the fontkit instance:

import { PDFDocument } from 'pdf-lib'
import fontkit from '@pdf-lib/fontkit'

const pdfDoc = await PDFDocument.create()
pdfDoc.registerFontkit(fontkit)

Fontkit UMD Module

The following builds are available:

NOTE: if you are using the CDN scripts in production, you should include a specific version number in the URL, for example:

When using a UMD build, you will have access to a global window.fontkit variable. To register the fontkit instance:

var pdfDoc = await PDFLib.PDFDocument.create()
pdfDoc.registerFontkit(fontkit)

Documentation

API documentation is available on the project site at https://pdf-lib.js.org/docs/api/.

The repo for the project site (and generated documentation files) is located here: https://github.com/Hopding/pdf-lib-docs.

Fonts and Unicode

When working with PDFs, you will frequently come across the terms "character encoding" and "font". If you have experience in web development, you may wonder why these are so prevalent. Aren't they just annoying details that you shouldn't need to worry about? Shouldn't PDF libraries and readers be able to handle all of this for you like web browsers can? Unfortunately, this is not the case. The nature of the PDF file format makes it very difficult to avoid thinking about character encodings and fonts when working with PDFs.

pdf-lib does its best to simplify things for you. But it can't perform magic. This means you should be aware of the following:

  • There are 14 standard fonts defined in the PDF specification. They are as follows: Times Roman (normal, bold, and italic), Helvetica (normal, bold, and italic), Courier (normal, bold, and italic), ZapfDingbats (normal), and Symbol (normal). These 14 fonts are guaranteed to be available in PDF readers. As such, you do not need to embed any font data if you wish to use one of these fonts. You can use a standard font like so:
    import { PDFDocument, StandardFonts } from 'pdf-lib'
    const pdfDoc = await PDFDocument.create()
    const courierFont = await pdfDoc.embedFont(StandardFonts.Courier)
    const page = pdfDoc.addPage()
    page.drawText('Some boring latin text in the Courier font', {
      font: courierFont,
    })
    
  • The standard fonts do not support all characters available in Unicode. The Times Roman, Helvetica, and Courier fonts use WinAnsi encoding (aka Windows-1252). The WinAnsi character set only supports 218 characters in the Latin alphabet. For this reason, many users will find the standard fonts insufficient for their use case. This is unfortunate, but there's nothing that PDF libraries can do to change this. This is a result of the PDF specification and its age. Note that the ZapfDingbats and Symbol fonts use their own specialized encodings that support 203 and 194 characters, respectively. However, the characters they support are not useful for most use cases. See here for an example of all 14 standard fonts.
  • You can use characters outside the Latin alphabet by embedding your own fonts. Embedding your own font requires to you load the font data (from a file or via a network request, for example) and pass it to the embedFont method. When you embed your own font, you can use any Unicode characters that it supports. This capability frees you from the limitations imposed by the standard fonts. Most PDF files use embedded fonts. You can embed and use a custom font like so (see also):
    import { PDFDocument } from 'pdf-lib'
    import fontkit from '@pdf-lib/fontkit'
    
    const url = 'https://pdf-lib.js.org/assets/ubuntu/Ubuntu-R.ttf'
    const fontBytes = await fetch(url).then((res) => res.arrayBuffer())
    
    const pdfDoc = await PDFDocument.create()
    
    pdfDoc.registerFontkit(fontkit)
    const ubuntuFont = await pdfDoc.embedFont(fontBytes)
    
    const page = pdfDoc.addPage()
    page.drawText('Some fancy Unicode text in the ŪЬȕǹƚü font', {
      font: ubuntuFont,
    })
    

Note that encoding errors will be thrown if you try to use a character with a font that does not support it. For example, Ω is not in the WinAnsi character set. So trying to draw it on a page with the standard Helvetica font will throw the following error:

Error: WinAnsi cannot encode "Ω" (0x03a9)
    at Encoding.encodeUnicodeCodePoint

Font Subsetting

Embedding a font in a PDF document will typically increase the file's size. You can reduce the amount a file's size is increased by subsetting the font so that only the necessary characters are embedded. You can subset a font by setting the subset option to true. For example:

const font = await pdfDoc.embedFont(fontBytes, { subset: true });

Note that subsetting does not work for all fonts. See https://github.com/Hopding/pdf-lib/issues/207#issuecomment-537210471 for additional details.

Creating and Filling Forms

pdf-lib can create, fill, and read PDF form fields. The following field types are supported:

See the form creation and form filling usage examples for code samples. Tests 1, 14, 15, 16, and 17 in the complete examples contain working example code for form creation and filling in a variety of different JS environments.

IMPORTANT: The default font used to display text in buttons, dropdowns, option lists, and text fields is the standard Helvetica font. This font only supports characters in the latin alphabet (see Fonts and Unicode for details). This means that if any of these field types are created or modified to contain text outside the latin alphabet (as is often the case), you will need to embed and use a custom font to update the field appearances. Otherwise an error will be thrown (likely when you save the PDFDocument).

You can use an embedded font when filling form fields as follows:

import { PDFDocument } from 'pdf-lib';
import fontkit from '@pdf-lib/fontkit';

// Fetch the PDF with form fields
const formUrl = 'https://pdf-lib.js.org/assets/dod_character.pdf';
const formBytes = await fetch(formUrl).then((res) => res.arrayBuffer());

// Fetch the Ubuntu font
const fontUrl = 'https://pdf-lib.js.org/assets/ubuntu/Ubuntu-R.ttf';
const fontBytes = await fetch(fontUrl).then((res) => res.arrayBuffer());

// Load the PDF with form fields
const pdfDoc = await PDFDocument.load(formBytes);

// Embed the Ubuntu font
pdfDoc.registerFontkit(fontkit);
const ubuntuFont = await pdfDoc.embedFont(fontBytes);

// Get two text fields from the form
const form = pdfDoc.getForm();
const nameField = form.getTextField('CharacterName 2');
const ageField = form.getTextField('Age');

// Fill the text fields with some fancy Unicode characters (outside
// the WinAnsi latin character set)
nameField.setText('Ӎӑȑїõ');
ageField.setText('24 ŷȇȁŗš');

// **Key Step:** Update the field appearances with the Ubuntu font
form.updateFieldAppearances(ubuntuFont);

// Save the PDF with filled form fields
const pdfBytes = await pdfDoc.save();

Handy Methods for Filling, Creating, and Reading Form Fields

Existing form fields can be accessed with the following methods of PDFForm:

New form fields can be created with the following methods of PDFForm:

Below are some of the most commonly used methods for reading and filling the aforementioned subclasses of PDFField:





Limitations

  • pdf-lib can extract the content of text fields (see PDFTextField.getText), but it cannot extract plain text on a page outside of a form field. This is a difficult feature to implement, but it is within the scope of this library and may be added to pdf-lib in the future. See #93, #137, #177, #329, and #380.
  • pdf-lib can remove and edit the content of text fields (see PDFTextField.setText), but it does not provide APIs for removing or editing text on a page outside of a form field. This is also a difficult feature to implement, but is within the scope of pdf-lib and may be added in the future. See #93, #137, #177, #329, and #380.
  • pdf-lib does not support the use of HTML or CSS when adding content to a PDF. Similarly, pdf-lib cannot embed HTML/CSS content into PDFs. As convenient as such a feature might be, it would be extremely difficult to implement and is far beyond the scope of this library. If this capability is something you need, consider using Puppeteer.

Help and Discussion

Discussions is the best place to chat with us, ask questions, and learn more about pdf-lib!

See also MAINTAINERSHIP.md#communication and MAINTAINERSHIP.md#discord.

Encryption Handling

pdf-lib does not currently support encrypted documents. You should not use pdf-lib with encrypted documents. However, this is a feature that could be added to pdf-lib. Please create an issue if you would find this feature helpful!

When an encrypted document is passed to PDFDocument.load(...), an error will be thrown:

import { PDFDocument, EncryptedPDFError } from 'pdf-lib'

const encryptedPdfBytes = ...

// Assignment fails. Throws an `EncryptedPDFError`.
const pdfDoc = PDFDocument.load(encryptedPdfBytes)

This default behavior is usually what you want. It allows you to easily detect if a given document is encrypted, and it prevents you from trying to modify it. However, if you really want to load the document, you can use the { ignoreEncryption: true } option:

import { PDFDocument } from 'pdf-lib'

const encryptedPdfBytes = ...

// Assignment succeeds. Does not throw an error.
const pdfDoc = PDFDocument.load(encryptedPdfBytes, { ignoreEncryption: true })

Note that using this option does not decrypt the document. This means that any modifications you attempt to make on the returned PDFDocument may fail, or have unexpected results.

You should not use this option. It only exists for backwards compatibility reasons.

Contributing

We welcome contributions from the open source community! If you are interested in contributing to pdf-lib, please take a look at the CONTRIBUTING.md file. It contains information to help you get pdf-lib setup and running on your machine. (We try to make this as simple and fast as possible! :rocket:)

Maintainership

Check out MAINTAINERSHIP.md for details on how this repo is maintained and how we use issues, PRs, and discussions.

Tutorials and Cool Stuff

Prior Art

  • pdfkit is a PDF generation library for Node and the Browser. This library was immensely helpful as a reference and existence proof when creating pdf-lib. pdfkit's code for font embedding, PNG embedding, and JPG embedding was especially useful.
  • pdf.js is a PDF rendering library for the Browser. This library was helpful as a reference when writing pdf-lib's parser. Some of the code for stream decoding was ported directly to TypeScript for use in pdf-lib.
  • pdfbox is a PDF generation and modification library written in Java. This library was an invaluable reference when implementing form creation and filling APIs for pdf-lib.
  • jspdf is a PDF generation library for the browser.
  • pdfmake is a PDF generation library for the browser.
  • hummus is a PDF generation and modification library for Node environments. hummus is a Node wrapper around a C++ library, so it doesn't work in many JavaScript environments - like the Browser or React Native.
  • react-native-pdf-lib is a PDF generation and modification library for React Native environments. react-native-pdf-lib is a wrapper around C++ and Java libraries.
  • pdfassembler is a PDF generation and modification library for Node and the browser. It requires some knowledge about the logical structure of PDF documents to use.

Git History Rewrite

This repo used to contain a file called pdf_specification.pdf in the root directory. This was a copy of the PDF 1.7 specification, which is made freely available by Adobe. On 8/30/2021, we received a DMCA complaint requiring us to remove the file from this repo. Simply removing the file via a new commit to master was insufficient to satisfy the complaint. The file needed to be completely removed from the repo's git history. Unfortunately, the file was added over two years ago, this meant we had to rewrite the repo's git history and force push to master 😔.

Steps We Took

We removed the file and rewrote the repo's history using BFG Repo-Cleaner as outlined here. For full transparency, here are the exact commands we ran:

$ git clone [email protected]:Hopding/pdf-lib.git
$ cd pdf-lib
$ rm pdf_specification.pdf
$ git commit -am 'Remove pdf_specification.pdf'
$ bfg --delete-files pdf_specification.pdf
$ git reflog expire --expire=now --all && git gc --prune=now --aggressive
$ git push --force

Why Should I Care?

If you're a user of pdf-lib, you shouldn't care! Just keep on using pdf-lib like normal 😃 ✨!

If you are a pdf-lib developer (meaning you've forked pdf-lib and/or have an open PR) then this does impact you. If you forked or cloned the repo prior to 8/30/2021 then your fork's git history is out of sync with this repo's master branch. Unfortunately, this will likely be a headache for you to deal with. Sorry! We didn't want to rewrite the history, but there really was no alternative.

It's important to note that pdf-lib's source code has not changed at all. It's exactly the same as it was before the git history rewrite. The repo still has the exact same number of commits (and even the same commit contents, except for the commit that added pdf_specification.pdf). What has changed are the SHAs of those commits.

The simplest way to deal with this fact is to:

  1. Reclone pdf-lib
  2. Manually copy any changes you've made from your old clone to the new one
  3. Use your new clone going forward
  4. Reopen your unmerged PRs using your new clone

See this StackOverflow answer for a great, in depth explanation of what a git history rewrite entails.

License

MIT