Amazon is comfortably the world's largest bookstore. But it doesn't have all the books in the world (yet!).

Of course, the list of niche books that are missing is endless. However, there are also plenty of popular titles that are not on the platform, often because of licensing and agreement issues with the various publishers.

If you own a Kindle and want to grab some new titles to read, it makes sense to broaden your search. Here are some of the best websites other than Amazon to find great Kindle books.

1. ManyBooks

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ManyBooks has been around since 2004. It offers more than 50,000 free ebooks for you to download.

While it was originally a repo of out-of-copyright books, the site's mandate has since expanded. Today, it is also a platform in which authors can self-publish their own titles, meaning new books are being added to the site's collection every day.

Make sure you also keep your eyes peeled for ManyBooks' “Daily Deals”. You will find many popular books being given away for free. The deals change every 24 hours.

2. Smashwords

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Smashwords is the world's largest distributor of indie ebooks (yes, even bigger than Amazon). Authors can use the platform to self-publish their works then distribute the books to retailers and libraries.

The site offers more than 400,000 books in total, of which more than 70,000 can be downloaded for free.

To take full advantage of Smashwords, you need to make an account. Doing so means you will be able to start searching on the site, as well as use the site's excellent ebook library management tools.

3. Open Library

open library

The Internet Archive is well-known for its selection of free content across a number of different media formats. Many people do not realize, however, that the site has created a spinoff service called Open Library.

The concept behind the project is to make a page on the site for every book ever made. For literary geeks, that's going to be great. However, from the standpoint of a regular reader, the site has a Classic Books section where you can download more than three million Kindle books for free.

As well as the classic books, the site has a section where you can borrow modern books for free.

4. Project Gutenberg

project gutenberg

Project Gutenberg is a perennial favorite on lists of this nature. It boasts more than 60,000 free ebooks that you can read on your Kindle.

You can't download the books directly onto your Kindle from the site, so you will have to be comfortable using an ebook management app like Calibre.

However, given that the site boasts hundreds of titles that are not available anywhere else, we think it is a small price to pay.

On the downside, you're not going to find the latest ebook releases on Project Gutenberg. It primarily stocks older titles that are no longer covered by copyright protections.

5. OverDrive

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Most public libraries in the US have a subscription to OverDrive. It lets you borrow free ebooks from your library in the same way that you would borrow a regular physical book.

The beauty of OverDrive is that you will never need to worry about returning a book. Once your allotted time expires, the book will be automatically removed from your Kindle, meaning you will never have to pay a late fee again.

You don't even need to visit your library in person to use the service. OverDrive has made a free smartphone app (available on Android and iOS) called Libby. It lets you borrow ebooks remotely.

6. Book Lending

book lending

The sharing economy is a big thing right now, and Book Lending has tried to port that to the world of borrowing books.

Not only does the app let you borrow books, but it also lets you loan out your own books. This is perfect if you have some rare titles in your collection that you think other Kindle owners would enjoy.

All book loans made via Book Lending are only available for 14 days, so make sure you start reading soon after you make your decision to borrow a title.

7. Centsless Books

centsless

Centsless Books offers free Kindle ebooks across a wide range of categories. Some of the most popular categories include sci-fi, biographies and memoirs, self-help, teen, comics, parenting and relationships, and travel. In total, there are more than 30 categories for you to dig into.

The site is exceptionally easy to navigate. Just click on the category you want to explore in the left-hand menu, then browse the thumbnails to find a book you want.

8. eBooks.com

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eBooks.com is one of the largest ebooks sellers on the web. It has more than two million books for you to choose from, with a variety of free and paid titles.

Sadly, ebooks.com does not sell ebooks in the MOBI or AZW format. You can only download in EPUB or PDF. That means you will need to use Calibre to convert your ebooks before you add them to your Kindle device. Online ebook conversion sites are also available.

9. Harlequin

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If you want to buy Kindle books written for and aimed at women, Harlequin is probably the best store you will be able to find.

The site is a project by publishing behemoth HarperCollins and thus has a steady flow of new (and more importantly, high quality) content. Around 100 new books are made available on the site every month.

The main categories on Harlequin are romance, thrillers, suspense novels, small-town dramas, and paranormal stories.

10. Blackwell's

blackwells

Blackwell's is a great place to buy Kindle ebooks if you live in the UK and do not want to use Amazon's store.

The site has both an ebook section and a physical book section, with sections such as Computing, Languages, Reference, Sports, Music, Medical, Business, and Art.

We especially like Blackwell's ebook collections. Shared with readers in the form of articles, they are curated lists around a theme. For example, at the time of writing, there are curated lists available for "Back to University" and "Autumn Highlights."

Don't Stick to Amazon

Amazon is undoubtedly a fantastic resource for ebooks, especially if you are a Kindle owner. However, as this list has demonstrated, it is far from being the only option.

If you want to support smaller companies, find indie writers, or even borrow books rather than buy them, the options we have covered might be better Kindle ebook stores for you.