Academic Book PDF Merger

A Chrome extension that downloads individual chapter PDFs from academic publisher book pages and merges them into a single PDF file.

The Problem

Many academic publishers (Oxford Academic, etc.) provide access to book chapters as individual PDFs. Downloading and combining 20+ chapter PDFs manually is tedious and time-consuming.

The Solution

This extension adds a one-click workflow: select chapters, click merge, get a single PDF. It runs entirely in the browser using your existing institutional/personal authentication -- no external servers, no API keys, no credentials to share.

Supported Publishers

Publisher	Status	Domain
Oxford Academic (OUP)	Supported	academic.oup.com
Cambridge University Press (CUP)	Supported	cambridge.org
JSTOR	Planned (#4)
Springer	Planned
Wiley	Planned

Features

• Chapter selection: View the full table of contents with checkboxes, grouped by section/part. All selected by default, deselect what you don't need.
• Job queue: Queue multiple books from different tabs. Jobs run concurrently in the background.
• Background processing: Closing the popup doesn't cancel the merge. Reopen to check progress.
• Progress tracking: Real-time progress bar and detailed log for each job.
• In-browser merging: Uses pdf-lib for client-side PDF merging. No data leaves your browser.
• Configurable: Set download folder, request delay, and more in extension settings.

Installation

From source (developer mode)

1. Clone this repository:

   git clone https://github.com/gr0esch/Academic-Book-PDF-Merger.git

2. Open Chrome and navigate to chrome://extensions/
3. Enable Developer mode (toggle in the top-right corner)
4. Click Load unpacked
5. Select the extension/ folder from this repository

From Chrome Web Store

Not yet published.

Usage

1. Navigate to a supported publisher's book page (e.g., a book on academic.oup.com)
2. Click the extension icon in the toolbar
3. The chapter list appears with all chapters selected by default
4. Deselect any chapters you don't need (front matter, index, etc.)
5. Click Download & Merge PDF
6. The job runs in the background -- you can close the popup, switch tabs, or queue more books
7. The merged PDF is saved to your Downloads folder (subfolder configurable in settings)

Settings

Right-click the extension icon and select Options, or go to chrome://extensions and click Details > Extension options.

Setting	Default	Description
Download subfolder	Academic_Books	Subfolder within your Downloads directory
Request delay	500ms	Delay between chapter fetches to avoid rate limiting
Save As dialog	Off	Whether to show a file picker for each merged PDF

How It Works

1. Content script detects the publisher and scrapes the chapter list from the book's table of contents page
2. Background service worker orchestrates the merge job:
   • For each chapter, fetches the chapter page (in the page's context, with your session cookies) to find the PDF download link
   • Opens each PDF URL in a hidden background tab (browser-native request, uses your authentication)
   • Extracts the PDF bytes from the loaded tab
   • Merges all PDFs in order using pdf-lib
   • Triggers the final download via the Chrome downloads API

Architecture

extension/
  manifest.json         # Chrome MV3 manifest
  background.js         # Service worker: job queue, merge orchestration
  content.js            # Content script: publisher detection + chapter scraping
  offscreen.html/js     # Offscreen document: blob URL creation for downloads
  popup/
    popup.html/js/css   # Extension popup: chapter selection + job queue UI
  options/
    options.html/js     # Settings page
  lib/
    pdf-lib.min.js      # PDF merging library (client-side)
  icons/
    icon16/48/128.png   # Extension icons

Adding a New Publisher

1. Open content.js
2. Add a new provider object to the providers array:

   {
     name: "Publisher Name",
     detect() {
       // Return true if the current page is a book TOC for this publisher
       return document.querySelector(".some-unique-selector") !== null;
     },
     scrape() {
       // Return { provider, bookTitle, baseUrl, chapters, pdfLinkSelector, pdfLinkFallback }
       // chapters: [{ id, number, title, section, href }]
     },
   }

3. Add the publisher's domain to host_permissions in manifest.json
4. The background worker handles the rest -- it uses the pdfLinkSelector from your provider to find PDF links on chapter pages

Requirements

• Google Chrome (version 116+ for Manifest V3 + offscreen API)
• Institutional or personal access to the publisher's content (the extension uses your existing browser session)

Privacy

• No data collection: The extension does not collect, transmit, or store any personal data
• No external servers: All processing happens locally in your browser
• Session-based: Uses your existing browser session for authentication -- no credentials are stored or transmitted by the extension
• Permissions are scoped: Host permissions are limited to supported publisher domains

License

MIT