Everyone is paying for books when they don’t have to. There’s so many ways to read almost anything ever published, for free, that it borders on the obscene. Libraries: They’re good! Sure, if you want the latest release from your favorite author you either have to pay or wait for a copy from the library, but for millions of older books, you can get a digital version, legally, for free. One secret of the publishing industry is that most American books published before 1964 never extended their copyright, meaning they’re in the public domain today.

Why millions of books entered public domain with no one knowing

Prior to 1964, books had a 28-year copyright term. Extending it required authors or publishers to send in a separate form, and lots of people didn’t end up doing that. Thanks to the efforts of the New York Public Library, many of those public domain books are now free online. Through the 1970s, the Library of Congress published the Catalog of Copyright Entries, all the registration and renewals of America’s books. The Internet Archive has digital copies of these, but computers couldn't read all the information and figuring out which books were public domain, and thus could be uploaded legally, was tedious. The actual, extremely convoluted specifics of why these books are in the public domain are detailed in a post by the New York Public Library, which recently paid to parse the information in the Catalog of Copyright Entries.

In a massive undertaking, the NYPL converted the registration and copyright information into an XML format. Now, the old copyrights are searchable and we know when, and if, they were renewed. Around 80 percent of all the books published from 1923 to 1964 are in the public domain, and lots of people had no idea until now.

Where to download these free Public domain eBooks

It amounts to an explosion of new books once lost to the mire of potential copyright claims. And they’re all free. The Hathi Trust, a digital library similar to Project Gutenberg, has already uploaded some of the newly freed books. Leonard Richardson, a blogger and programer in New York City, has been following the saga of the newly public domain books and writing about it on his site News You Can Bruise.

When the books started hitting the internet, Richardson created a Mastodon bot called Secretly Public Domain which posts a newly discovered book from the collection every day.

“The public domain belongs to everybody,” Richardson said in an email. “I think this is really important in a world where popular culture is increasingly owned by a few companies. You can read a public domain book for free, and you can use it as raw material for your creativity without asking permission. And once someone makes a good electronic copy of a public domain work, it's less likely to be lost forever than an in-copyright work.”

Richardson has already found a few books he’s personally interested in. “I'm interested in computer history, so almost the first thing I did was check for that, but not a lot of computer books were published before the 1964 cutoff,” he said. “The first edition of The compatible time-sharing system:a programmer's guide was registered in 1963 and not renewed; that book describes a system that's pretty important to the history of computing.”

Guttenberg and Hathi aren’t the only places to get free books. Many libraries offer digital and audio books, for free, as a benefit of membership. Reading a classic or a new release can be a simple as getting a library card and downloading an app. “For high-quality electronic presentations of public domain titles I recommend Standard Ebooks,” Richardson said. “They're a real pleasure to read.”