Book Creator online
With the free plan, you get 1 library and 40 books for free. You can free up space by deleting or combining books, and you can even start again by archiving the library and creating a fresh one.
With the paid plan you get unlimited libraries with up to 200 books in each and you can have up to 1000 books.
When it comes to storage space inside the book, all of the text and media you add to the page is stored on our servers so you don't have to worry about running out of space on your computer. You just need to bear in mind that books with lots of images and video in them may take longer to load (especially if you don't have a fast internet connection). And if you want to download the book, you need to consider the file size of the book, and where you will store it offline.
Book Creator for iPad
With the full version of Book Creator for iPad you can create unlimited books - but remember, each book you create is saved locally on your iPad so you'll need to check how much storage space you have on your iPad (you can do that in Settings > General > iPad Storage).
Much like Book Creator online, be aware that if you're adding lots of media to your book, the file size will increase. You can check the current file size of the book by tapping on the title of the book on the bookshelf (listed as 'iBook file size').
How many pages can I add to the book?
Technically, you can create 9,999 pages in your book! But it's unlikely anyone will need that many. You need to remember that more pages will mean the file size of your book is bigger. Read more about this here.