Open Library is like a gigantic online card catalog. The Internet Archive (one of the most underrated entertainment sites on the Web) is working on the ambitious project to have one web page for every book ever published. The catalog is made up of millions of titles of fiction, nonfiction, textbooks, and children’s books.
You can read many of them instantly in your browser. Others are available by borrowing with a free account. (It’s not too different from checking out real books at your local library. They have waiting lists for the popular stuff, but there are so many books, you’ll always have plenty of choices.) I like the Reading Goal and Virtual Library features, too. And if you’ve ever thought you might be a librarian in another life, the site allows for all kinds of open source, collaborative ways to get involved.
https://openlibrary.org/