Some developers package their scripts into standalone applications.
Most public libraries offer free e-book loans. Libby (by OverDrive) allows you to send borrowed EPUB files to your Kindle or Kobo. This is 100% legal and supports authors. google books downloader github
python download.py --id "ABC123def" --start 1 --end 200 --output mybook.pdf This is 100% legal and supports authors
for purchased titles, many users turn to open-source tools on GitHub to download "previewable" or "snippet view" books for offline research. These GitHub projects typically use Python scripts or browser-based JavaScript to automate the process of capturing page images and stitching them into PDFs. Top Google Books Downloaders on GitHub Top Google Books Downloaders on GitHub : A
: A Python 3 program that downloads high-resolution images of previewable pages using proxies to maximize the page count, then combines them into a PDF.