Google Play Books downloader for interoperability purposes. Each page is downloaded as an image, it's up to you to build a PDF from them, do OCR, and add metadata.

Why:

• Google Play Books has two reading modes:
  • Flowing text: EPUB file. You can download it from your Google Play Books library, when available.
  • Original Pages: PDF file. Usually provided to Google by the book publisher, or sometimes scanned by Google themselves (where each page is a big image). You can download this PDF from Google Play Books, but only if Google (arbitrarily) decides that its size is small enough.
• The Google Play Reader app isn't available on all platforms (e.g. e-ink tablets) but fortunately you can download an EPUB or a PDF file. You can then read the downloaded book on any platform, provided that it supports the Adobe Digital Editions DRM.
• Problem: Many PDFs are not available for download because Google unilaterally decides that they are “large book files” ( vague term for which they provide no definition). Due to that you can't read the book (that you bought!) on the platform of your choice.

Note: this script only works for books that have the “Original Pages” viewing option.

Prequisites

• Install zx.
• Install Python and Poetry.
• Download and extract the project repository.

Usage

• Open google-play-book-downloader-pdf.mjs and edit the following constants:

  • BOOK_ID: the ID of the book. You can find it in the URL to the book page. Example: BwCMEAAAQBAJ
  • FETCH_OPTIONS: the headers and cookies that are necessary to send requests on your behalf. Here is how to get it:
    1. Go to https://play.google.com/books and log in.
    2. Open dev console, network tab.
    3. Click on a random link in the page.
    4. Right-click on the corresponding request in the dev console and then Copy as Node.js fetch.
    5. Paste the object inside FETCH_OPTIONS. The object that you need is the second argument in the call to fetch().

• Run the script from the repository folder:

zx google-play-book-downloader-pdf.mjs

You will find the downloaded book pages in the books/[BOOK_ID] folder.

Recommended next steps:

1. Optimize the resulting images:

   a) Run pngquant. It does high-quality lossy compression (40-70%) on the PNG images by optimizing the color palette:

   pngquant -fv --ext=.png --skip-if-larger --speed=1 --quality=95-100 *.png
   

   b) (Optional) Run oxipng. It does additional lossless compression (3-5%) on the PNG images produced by pngquant:

   oxipng --dir . --strip safe --interlace 0 -o 4 *.png
   

2. Build a PDF

   This command will merge all the pages into a PDF, add metadata (book title, date, authors, etc.), and a table of contents.

   Run the following command (replace [BOOK_ID] with the ID of the book):

   poetry run play-book-pdf-build books/[BOOK_ID]
   

3. OCR and optimize the PDF using Adobe Acrobat Pro:

   a) Open the PDF.

   b) [Menu] Tools → Scan → OCR.

   c) [Scan & OCR toolbar] → Settings:

   • Tick All pages.
   • Set Document Language to the correct one (e.g. English).
   • Set Output to Searchable Image (Exact) (important!).
   • Press OK.

   d) [Scan & OCR toolbar] → Recognize Text.

   e) [Menu] File → Save as Other → Optimized PDF….

   • Untick everything, except section [Cleanup].
   • Section [Cleanup]
     • Tick Optimize the PDF for fast web view and untick everything else. This option makes Adobe Acrobat reorganize the structure of the PDF to be linear. This enables PDF viewers to quickly display the PDF while it's still downloading in the background.
     • Set Object compression options to Leave compression unchanged.
   • Click on OK.