All seven Harry Potter books are now available in the Kindle Owners' Lending Library, marking the series' first availability outside the Pottermore store.
The books became available Tuesday to Amazon Prime users, who may borrow one book a month from the lending library.
“Nowhere else can customers borrow any of the seven Harry Potter books for free, with an unlimited supply of each title and no waiting list,” said Russ Grandinetti, Kindle content vice president, in a statement.
Amazon Prime customers pay $79 a year for two-day delivery on all of their Amazon purchases, access to the more than 145,000 titles in the lending library and the ability to stream from Amazon's collection of more than 18,000 movies and TV episodes.
The Harry Potter books, the best selling series of all time, became available through a licensing agreement between Amazon and the Pottermore website. Previously, e-books of the series where only available from Pottermore after launching there in late March.