How to Split a PDF file into Separate PDF Documents

This tutorial describes how to extract pages from a PDF document from the command line. There are online tools available for splitting PDFs but if you prefer not to share your PDF files with a third-party, you can split them into separate pages easily from the command line.

Split PDF Files

Assuming that you have node installed on your computer, run the following command in the terminal to initialize the environment:

$ mkdir pdf-split
$ cd pdf-split
$ npm init -y

Next, we’ll install the popular pdf-lib package from the npm registry. PDF library is written in TypeScript and it is a very tool for creating and manipulating PDF files. You can learn more about PDF library at js.org.

In addition to splitting PDF files, the PDF library can also be used for merging multiple PDF files into a single PDF file. Or for rearranging the pages of a PDF file.

$ npm install --save pdf-lib

Next, we’ll write a simple Node.js script that splits a PDF file into multiple PDF files. You need to provide the path of the input PDF file and the output folder.

// split.pdf.js
const fs = require('fs');
const path = require('path');
const { PDFDocument } = require('pdf-lib');

const splitPDF = async (pdfFilePath, outputDirectory) => {
  const data = await fs.promises.readFile(pdfFilePath);
  const readPdf = await PDFDocument.load(data);
  const { length } = readPdf.getPages();

  for (let i = 0, n = length; i < n; i += 1) {
    const writePdf = await PDFDocument.create();
    const [page] = await writePdf.copyPages(readPdf, [i]);
    writePdf.addPage(page);
    const bytes = await writePdf.save();
    const outputPath = path.join(outputDirectory, `Invoice_Page_${i + 1}.pdf`);
    await fs.promises.writeFile(outputPath, bytes);
    console.log(`Added ${outputPath}`);
  }
};

splitPDF('input/invoices.pdf', 'invoices').then(() =>
  console.log('All invoices have been split!').catch(console.error)
);

In the above example, we have a large PDF file that contains multiple invoices generated from the Tally accounting system. We want to split the PDF file into multiple PDF files such that each invoice is a separate PDF file.

You can run the above script in the terminal to split the PDF file.

$ node split.pdf.js

Compress Large PDF files

The one downside of this approach is that the generated PDF files are large in size. You can however use the ghostscript command line utility to highly compress the size of split PDF files.

gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.2 -r200 -dPDFSETTINGS=/screen -dEmbedAllFonts=true -dSubsetFonts=true -dPrinted=false -dNOPAUSE -dQUIET -dBATCH -sOutputFile=c12_{filename} {filename}

Also see: Useful FFMPEG Commands