unpdf
A collection of utilities to work with PDFs. Designed specifically for Deno, workers and other nodeless environments.
unpdf ships with a serverless build/redistribution of Mozilla's PDF.js for serverless environments. Apart from some string replacements and mocks, unenv does the heavy lifting by converting Node.js specific code to be platform-agnostic. See pdfjs.rollup.config.ts for all the details.
This library is also intended as a modern alternative to the unmaintained but still popular pdf-parse.
Features
- 🏗️ Works in Node.js, browser and workers
- 🪭 Includes serverless build of PDF.js (
unpdf/pdfjs) - 💬 Extract text and images from PDFs
- 🧱 Opt-in to legacy PDF.js build
- 💨 Zero dependencies
PDF.js Compatibility
Note
This package is currently using PDF.js v4.0.189.
Installation
Run the following command to add unpdf to your project.
# pnpm
pnpm add unpdf
# npm
npm install unpdf
# yarn
yarn add unpdfUsage
Extract Text From PDF
import { extractText, getDocumentProxy } from "unpdf";
// Fetch a PDF file from the web
const buffer = await fetch(
"https://www.w3.org/WAI/ER/tests/xhtml/testfiles/resources/pdf/dummy.pdf",
).then((res) => res.arrayBuffer());
// Or load it from the filesystem
const buffer = await readFile("./dummy.pdf");
// Load PDF from buffer
const pdf = await getDocumentProxy(new Uint8Array(buffer));
// Extract text from PDF
const { totalPages, text } = await extractText(pdf, { mergePages: true });Access the PDF.js API
This will return the resolved PDF.js module and gives full access to the PDF.js API, like:
getDocumentversion- … and all other methods
Especially useful for platforms like 🦕 Deno or if you want to use the PDF.js API directly. If no custom build was defined beforehand, the serverless build bundled with unpdf will be initialized.
import { getResolvedPDFJS } from "unpdf";
const { getDocument } = await getResolvedPDFJS();
const data = Deno.readFileSync("dummy.pdf");
const doc = await getDocument(data).promise;
console.log(await doc.getMetadata());
for (let i = 1; i <= doc.numPages; i++) {
const page = await doc.getPage(i);
const textContent = await page.getTextContent();
const contents = textContent.items.map((item) => item.str).join(" ");
console.log(contents);
}Use Official or Legacy PDF.js Build
Generally speaking, you don't need to worry about the PDF.js build. unpdf ships with a serverless build of the latest PDF.js version. However, if you want to use the official PDF.js version or the legacy build, you can define a custom PDF.js module.
// Before using any other method, define the PDF.js module
// if you need another PDF.js build
import { configureUnPDF } from "unpdf";
await configureUnPDF({
// Use the official PDF.js build (make sure to install it first)
pdfjs: () => import("pdfjs-dist"),
});
// Now, you can use the other methods
// …Config
interface UnPDFConfiguration {
/**
* By default, UnPDF will use the latest version of PDF.js compiled for
* serverless environments. If you want to use a different version, you can
* provide a custom resolver function.
*
* @example
* // Use the official PDF.js build (make sure to install it first)
* () => import('pdfjs-dist')
*/
pdfjs?: () => Promise<PDFJS>;
}Methods
configureUnPDF
Define a custom PDF.js module, like the legacy build. Make sure to call this method before using any other methods.
function configureUnPDF(config: UnPDFConfiguration): Promise<void>;getResolvedPDFJS
Returns the resolved PDF.js module. If no build is defined, the latest version will be initialized.
function getResolvedPDFJS(): Promise<PDFJS>;getMeta
function getMeta(data: BinaryData | PDFDocumentProxy): Promise<{
info: Record<string, any>;
metadata: Record<string, any>;
}>;extractText
Extracts all text from a PDF. If mergePages is set to true, the text of all pages will be merged into a single string. Otherwise, an array of strings for each page will be returned.
function extractText(
data: BinaryData | PDFDocumentProxy,
{ mergePages }?: { mergePages?: boolean },
): Promise<{
totalPages: number;
text: string | string[];
}>;renderPageAsImage
Note
This method will only work in Node.js and browser environments.
To render a PDF page as an image, you can use the renderPageAsImage method. This method will return an ArrayBuffer of the rendered image.
In order to use this method, you have to meet the following requirements:
- Use the official PDF.js build
- Install the
canvaspackage in Node.js environments
Example
import { configureUnPDF, renderPageAsImage } from "unpdf";
await configureUnPDF({
// Use the official PDF.js build
pdfjs: () => import("pdfjs-dist"),
});
const pdf = await readFile("./dummy.pdf");
const buffer = new Uint8Array(pdf);
const pageNumber = 1;
const result = await renderPageAsImage(buffer, pageNumber, {
canvas: () => import("canvas"),
});
await writeFile("dummy-page-1.png", Buffer.from(result));Type Declaration
declare function renderPageAsImage(
data: BinaryData,
pageNumber: number,
options?: {
canvas?: () => Promise<typeof import("canvas")>;
/** @default 1 */
scale?: number;
width?: number;
height?: number;
},
): Promise<ArrayBuffer>;FAQ
Why Is canvas An Optional Dependency?
The official PDF.js library depends on the canvas module for Node.js environments, which doesn't work inside worker threads. That's why unpdf ships with a serverless build of PDF.js that mocks the canvas module.
However, to render PDF pages as images in Node.js environments, you need to install the canvas module. That's why it is a peer dependency.
License
MIT License © 2023-PRESENT Johann Schopplich