pdf-merger-ts

TypeScript rewrite of pdf-merger-js

All credit goes to the original author nbesli for creating the original library.

A TypeScript library to merge multiple PDF documents, or parts of them, to one new PDF document. Works in Node.js and directly in the browser.

The only dependency is pdf-lib so it can run in any JavaScript-only environment without any non-JavaScript dependencies.

Credits

This library is a TypeScript rewrite of pdf-merger-js by nbesli. The original library is an excellent JavaScript solution for PDF merging - this version adds full TypeScript support with type definitions included.

• Original Library: pdf-merger-js
• Original Author: nbesli
• License: MIT (same as original)

Installation

npm install --save pdf-merger-ts

Or for global CLI installation:

npm install -g pdf-merger-ts

Usage

CLI "pdf-merge"

Usage: pdf-merge [options] <inputFiles...>

merge multiple PDF documents, or parts of them, to a new PDF document

Options:
  -V, --version              output the version number
  -o, --output <outputFile>  Merged PDF output file path
  -v, --verbose              Print verbose output
  -s, --silent               do not print any output to stdout. Overwrites --verbose
  -h, --help                 display help for command

Example calls

Merge pages 1-2 from the first input with pages 1,2 and 5-7 from the second pdf document:

pdf-merge --output ./merged.pdf ./input1.pdf#1-2 ./input2.pdf#1,2,5-7

Node.js

The Node.js version has the following export functions:

• saveAsBuffer exports a merged PDF as a Buffer.
• save saves the PDF under the given filename.
• setMetadata sets metadata for producer, author, title or creator.
• reset resets the internal state of the document, to start again.

Example

import PDFMerger from 'pdf-merger-ts';

const merger = new PDFMerger();

await merger.add('pdf1.pdf');           // merge all pages
await merger.add('pdf2.pdf', 2);        // merge only page 2
await merger.add('pdf2.pdf', [1, 3]);   // merge pages 1 and 3
await merger.add('pdf2.pdf', '4, 7, 8'); // merge pages 4, 7 and 8
await merger.add('pdf3.pdf', '3 to 5'); // merge pages 3 to 5 (3,4,5)
await merger.add('pdf3.pdf', '3-5');    // merge pages 3 to 5 (3,4,5)

// Set metadata
await merger.setMetadata({
  producer: "pdf-merger-ts based script",
  author: "John Doe",
  creator: "John Doe",
  title: "My Document"
});

await merger.save('merged.pdf');

// Or export as Buffer:
// const mergedPdfBuffer = await merger.saveAsBuffer();

Browser

The browser version has the following export functions:

• saveAsBuffer exports a merged PDF as a Uint8Array.
• saveAsBlob exports a merged PDF as a Blob.
• save starts a file download directly in the browser.
• setMetadata sets metadata for producer, author, title or creator.
• reset resets the internal state of the document, to start again.

React Example

import PDFMerger from 'pdf-merger-ts/browser';
import React, { useEffect, useState } from 'react';

// files: Array of PDF File or Blob objects
const Merger = ({ files }: { files: File[] }) => {
  const [mergedPdfUrl, setMergedPdfUrl] = useState<string>();

  useEffect(() => {
    const render = async () => {
      const merger = new PDFMerger();

      for (const file of files) {
        await merger.add(file);
      }

      await merger.setMetadata({
        producer: "pdf-merger-ts based script"
      });

      const mergedPdf = await merger.saveAsBlob();
      const url = URL.createObjectURL(mergedPdf);

      setMergedPdfUrl(url);
    };

    render().catch(console.error);

    return () => {
      if (mergedPdfUrl) URL.revokeObjectURL(mergedPdfUrl);
    };
  }, [files]);

  return !mergedPdfUrl ? (
    <div>Loading...</div>
  ) : (
    <iframe
      height={1000}
      src={mergedPdfUrl}
      title="pdf-viewer"
      width="100%"
    />
  );
};

TypeScript Support

This library includes full TypeScript type definitions. The main types are:

import PDFMerger, { 
  Metadata,      // PDF metadata interface
  PdfInput,      // Valid input types
  PageSelection  // Page selection options
} from 'pdf-merger-ts';

API Differences from pdf-merger-js

This library maintains API compatibility with pdf-merger-js. You can switch by simply changing your import:

- import PDFMerger from 'pdf-merger-js';
+ import PDFMerger from 'pdf-merger-ts';

Similar Libraries

• pdf-merger-js - The original JavaScript library this is based on.
• pdf-lib - The underlying PDF library used for merging.
• pdf-merge - Has a dependency on PDFtk.
• easy-pdf-merge - Has a dependency on Apache PDFBox.

License

MIT - See LICENSE file for details.

This library is based on pdf-merger-js by nbesli. Thank you for the excellent work!