Amazon Kindle is a line of e-readers created and sold by Amazon. These devices let users look at, buy, download, and read e-books, newspapers, magazines, audiobooks, and other digital content using wireless internet to the Kindle Store. The technology for these devices was developed by Amazon's subsidiary, Lab126. It started with one model in 2007. Today, there are many kinds of devices, including e-readers with E Ink screens and Kindle apps for major computers. All Kindle devices work with Windows and macOS systems and connect to the Kindle Store. As of March 2018, the Kindle Store had more than six million e-books available in the United States.

Naming and evolution

In 2004, Jeff Bezos, who was the founder and CEO of Amazon, told his employees to create the best electronic reader in the world before other companies could. Amazon first called this device Fiona.

Branding experts Michael Cronan and Karin Hibma suggested the name "Kindle" for the device. Lab126 asked them to choose a name, and they picked "Kindle," which means to start a fire. They believed this name was a good way to describe the excitement of reading.

The Kindle devices changed over time, starting with the first Kindle in 2007 and the Kindle DX in 2009, which had a larger 9.7-inch screen. The DX was the only non-6-inch E Ink Kindle until 2017, when the Oasis 2 was introduced. Early models included devices with keyboards (Kindle Keyboard), screens that were touch-sensitive and had high resolution (Kindle Paperwhite), tablet computers with the Kindle app (Kindle Fire), and low-cost devices with touch-sensitive screens (Kindle 7). However, the Kindle was mostly designed for reading and not for other tasks that might distract users.

Active Content support was added in 2010 but was later removed from new Kindle devices in 2014. In 2014, the name "Kindle Fire" was changed to "Amazon Fire" to show that these devices could do more than just read books. Later models included devices with larger E Ink screens, such as the Kindle Oasis 2 (2017) with a 7-inch screen and the Paperwhite 5 (2021) with a 6.8-inch screen. In 2022, Amazon introduced the Kindle Scribe, which has a 10.2-inch screen and a stylus. Also in 2022, Amazon released the 11th generation Kindle with a 300 PPI display, ending the use of the 6-inch 167 PPI screen that had been on basic Kindles since 2007. In 2024, Amazon introduced the first color E Ink Kindle, the Kindle Colorsoft Signature Edition. In 2025, Amazon updated the Scribe lineup with a new design and introduced a Scribe Colorsoft model.

Amazon also offers Kindle apps for many devices, including Windows, macOS, Android, iOS, BlackBerry 10, and Windows Phone. Amazon provides a cloud reader that lets users read e-books using modern web browsers.

Features

Kindle devices can look up words in a dictionary or on Wikipedia when a user highlights a word in an e-book. Users can change the font type, size, and margins to suit their preferences. Kindles are charged by connecting them to a computer's USB port or an AC adapter. Users who need help reading because of vision problems can use an audio adapter to hear e-books read aloud on supported Kindles. Those who find it hard to read text may use the Amazon Ember Bold font for darker text, or other fonts with bold versions. Other fonts, like OpenDyslexic, are also available for accessibility.

The Kindle includes experimental features, such as a web browser based on NetFront and WebKit. This browser can access the Kindle Store and Wikipedia on 3G models, but may be limited to 50 MB of data per month for websites other than Amazon and Wikipedia. Other experimental features, depending on the model, include a Text-to-Speech engine that reads e-book text aloud and an MP3 player for playing music while reading.

The Kindle's operating system updates are received wirelessly and installed automatically during sleep mode when Wi-Fi is on. Users can also install firmware updates manually by downloading the firmware and copying it to the device's root directory. The Kindle uses the Linux kernel and a Java app for reading e-books.

Amazon initially allowed users to add content to their Kindle via email using a service called Personal Documents. Later, this was expanded to include cloud library features and content management. The modern version, called Send to Kindle, lets users send files like EPUB, PDF, HTML, Microsoft Word documents, GIF, PNG, and BMP graphics directly to their Kindle library. When Amazon receives a file, it converts it to Kindle File Format and stores it in the user's online library, called "Your Content." Files sent through Send to Kindle are added as Personal Documents by default, but some interfaces allow users to send files directly to a specific device without adding them to the library. These documents can be accessed on all Kindle hardware and on iOS and Android devices using the Kindle app.

Until August 2022, this service could also send unprotected and original version only .mobi/.azw files to a user's Kindle library. Sending files is free if done over Wi-Fi, but before 2021, it cost $0.15 per MB when using the former 3G service.

The first Kindle could read unprotected Mobipocket files (MOBI, PRC), plain text files (TXT), Topaz format books (TPZ), and Amazon's AZW format. The Kindle 2 added native PDF support with firmware version 2.3. The Kindle 1 could not read PDF files, but Amazon offered experimental conversion to AZW format, though not all PDFs may format correctly. The Kindle 2 also added support for Audible Enhanced (AAX) format and could display HTML files.

Fourth-generation and later Kindles, including Touch, Paperwhite (all generations), Voyage, and Oasis (all generations), can display AZW, AZW3, TXT, PDF, unprotected MOBI, and PRC files natively. HTML, DOC, DOCX, JPEG, GIF, PNG, and BMP files can be used through Amazon's conversion service. The Keyboard, Touch, Oasis 2 & 3, Kindle 8 & 9, and Paperwhite 4 can also play Audible Enhanced (AA, AAX) files. All Kindle models from the Paperwhite 2 and newer can display KFX files natively. KFX is Amazon's newer format replacing AZW3.

Kindles cannot display EPUB files natively. However, two methods allow EPUB content to be viewed:

• Software like Calibre can convert EPUB or other unsupported files to supported formats.
• Kindles can be jailbroken to install third-party apps like KOReader, which support EPUB.

In late April 2022, Amazon announced that Send to Kindle would support EPUB files, beginning in late 2022.

An e-book can be downloaded to multiple devices registered to the same Amazon account, up to a limit set by the publisher (usually one to six devices). If the limit is reached, the user must remove the e-book from a device or unregister a device to add it elsewhere.

The original Kindle and Kindle 2 did not allow users to organize books into folders. Users could only choose how content was displayed on the home screen and organize by author, title, or download date. Kindle software version 2.5 introduced "Collections," which act like tags or labels. A collection cannot include other collections, and one book may be added to multiple collections. Collections are set on the Kindle itself and can be transferred between devices. There is no option to organize by series or series order, as the AZW format lacks the necessary metadata.

X-Ray is a reference tool available on Kindle Touch and later devices, Fire tablets, the Kindle app for mobile platforms, and Fire TV. X-Ray lets users explore a book's content by accessing preloaded information, such as characters, locations, themes, or ideas.

Users can bookmark, highlight, and search content. Pages can be bookmarked for reference, and notes can be added to specific parts of a book. While reading, users can search for synonyms and definitions using the built-in dictionary. The device remembers the last page read for each book. Pages can be saved as "clippings," which are text files containing the displayed page's content. All clippings are saved in one file, which can be downloaded via USB. Because clippings are in TXT format, formatting like bold text or italics is removed.

On July 18, 2011, Amazon launched a program allowing college students to rent Kindle textbooks from three publishers for a fixed period.

Kindle devices may send reading data to Amazon, including the last page read, how long each e-book was opened, annotations, bookmarks, notes, highlights, or similar markings. This information is stored for all Amazon e-books, but it is unclear if it is stored for non-Amazon e-books. Amazon has access to user data, including the user's identity, what they are reading, whether they finished a book, their current page, time spent on each page, and highlighted passages.

Kindle ecosystem

Books from Amazon's Kindle Store are stored in special formats like .azw, .kf8, and .kfx. In addition to books, Kindle users can browse the internet using a special web browser called NetFront. Users can read books directly on the Kindle or through a web browser. The Kindle Store offers a service called Kindle Unlimited, which gives access to over one million e-books for a monthly fee.

Kindle content can be bought online and downloaded wirelessly in some countries using Wi-Fi or Amazon's 3G Whispernet network. Whispernet does not require a monthly fee, but extra charges may apply for downloading magazines or other content while traveling outside a user's home country. A feature called Whispersync lets users keep track of reading progress, bookmarks, and other details across Kindles and other devices. In December 2021, the 3G network was turned off for some Kindles because 3G services were no longer available.

For U.S. users traveling abroad, Amazon stopped charging a $1.99 fee for downloading e-books over 3G while overseas. However, fees still apply for downloading magazines or personal documents using 3G outside the user's home country. Wi-Fi downloads do not have extra charges.

Books for the Kindle can also be purchased from other sources, such as Fictionwise and Baen Ebooks. Free books from the public domain are available through services like Project Gutenberg, The Internet Archive, and the World Public Library. In 2011, the Kindle Store had more than twice as many paid books as Barnes & Noble, its closest competitor.

Public libraries that use OverDrive can lend Kindle-compatible books through an app called Libby. Users can borrow books from their library's website, which connects to Amazon to complete the checkout. The Libby app saves user and library information and sends the borrowed book to the user's Amazon account. Amazon then sends the book to the Kindle for the loan period. Some books may need to be transferred via a computer. If the same book is borrowed or purchased again, notes and bookmarks are saved.

Amazon released a Kindle app for computers in late 2009, which works on Windows systems. A version for Mac computers was released in early 2010. Apps for Android phones, Apple iOS devices, and BlackBerry phones followed in 2010 and 2011. A web-based version called Kindle Cloud Reader was introduced in 2011. Amazon did not create a separate app for Linux systems but said the Cloud Reader could be used on Linux browsers.

In 2014, Samsung stopped its own e-book store and partnered with Amazon to create a Kindle app for Samsung Galaxy devices. This app uses Amazon's e-book store and offers a limited number of free books each month.

In 2016, Amazon added a feature called Page Flip to its Kindle apps. This allows users to view nine pages at a time as thumbnails.

Amazon launched Kindle Direct Publishing in 2007, which lets authors and publishers upload books directly to the Kindle Store. Authors can charge between $0.99 and $200 per download.

In 2009, Amazon CEO Jeff Bezos told The New York Times that Amazon keeps 65% of e-book sales revenue, with the remaining 35% split between authors and publishers. Later, Amazon offered 70% royalties to Kindle publishers who agreed to specific rules, such as not allowing books to be borrowed by others.

In 2010, Amazon released the Kindle Development Kit (KDK), which helps developers create interactive content for the Kindle. The KDK uses Java programming tools and includes sample code and a simulator.

As of 2014, the Kindle Store had over 400 interactive books, games, and apps. These were only available to users with U.S. billing addresses.

In 2014, Amazon announced that new e-readers like the Voyage would not support interactive content because most users prefer apps on phones and tablets. However, older Kindles like the Paperwhite would continue to support interactive content.

Reception

Amazon does not share exact numbers of Kindle devices sold. However, anonymous sources said more than three million Kindles were sold by December 2009. Other estimates from that time suggested about 1.5 million devices sold. James McQuivey from Forrester Research estimated around four million Kindles were sold by mid-2010.

In 2010, Amazon was the top seller of e-readers, with 59% of all e-readers sold worldwide. This was an increase of 14 percentage points compared to earlier years. A study from March 2011 by International Data Corporation (IDC) showed that 12.8 million e-book readers were sold globally in 2010, and 48% of those were Kindles. In the last three months of 2010, Amazon reported that e-book sales in the United States had surpassed sales of paperback books for the first time.

In January 2011, Amazon said that digital books sold faster than printed books on its website, with 115 Kindle editions sold for every 100 paperback editions. In December 2011, Amazon stated that more than one million Kindles were sold each week since late November 2011. This included all Kindle models and the Kindle Fire tablet. IDC estimated that 4.7 million Kindle Fire devices were sold in the fourth quarter of 2011. Pacific Crest estimated that six million Kindle Fire models were sold in the fourth quarter of 2012.

Morgan Stanley estimated that Amazon sold $3.57 billion worth of Kindle devices and tablets in 2012, $4.5 billion in 2013, and $5 billion in 2014.

Amazon said its sales reached a record high before announcing new Kindle models in 2024.

Used Kindles in good condition can be sold, traded, donated, or recycled. Some people choose to donate Kindles to schools, developing countries, literacy programs, or charities. "The Kindle Classroom Project" gives donated Kindles to schools in need. Organizations like Worldreader and "Develop Africa" send donated e-readers to schools in Africa for education. "Project Hart" may accept donated e-readers to give to people in need.

Kindles should not be thrown away in normal trash because they contain electronic ink and batteries. Instead, they should be recycled. In the United States, Amazon offers a program called 'Take Back,' which lets owners print a prepaid shipping label to return the device for proper disposal.

Criticism

On July 17, 2009, Amazon stopped selling two e-books by George Orwell, Animal Farm and Nineteen Eighty-Four, and gave refunds to people who had bought them. Amazon also removed the books from customers' devices without warning using a hidden method called a backdoor. This happened because the publisher did not have the legal right to sell the books. The books were protected by copyright in the United States but were available for free in Canada, Australia, and other countries. Notes and comments added by users to the books were saved in a separate file but became unusable without the original text they were linked to. This action caused public concern and was compared to the novel Nineteen Eighty-Four, where books that disagree with the ruling party are destroyed or changed. People called Amazon's actions "Orwellian" because of this similarity. Ars Technica said the deletion broke the Kindle's rules, which stated that users should have control over their purchases.

Amazon said it would change its systems to prevent future removals of books from customers' devices. On July 23, 2009, Amazon's CEO, Jeff Bezos, apologized on the Kindle forum, calling the action "stupid" and admitting that Amazon's leaders deserved criticism.

On July 30, 2009, Justin Gawronski, a high school student, and Antoine Bruguier, an engineer, sued Amazon in a U.S. court. They claimed Amazon broke its terms of service by deleting Nineteen Eighty-Four without permission and prevented users from accessing their notes. The lawsuit asked for money and changes to Amazon's policies. The case was settled in September 2009, with Amazon paying $150,000 to the two men. The lawyers would give their share of the money to a charity. Amazon also gave Kindle users more rights over their e-books.

On September 4, 2009, Amazon offered users who lost books the option to restore them or receive a $30 gift card or check.

In December 2010, Amazon removed three e-books by Selena Kitt and other self-published authors because they included content about consensual incest, which Amazon said was offensive. Kitt claimed Amazon's rules were applied unfairly. The books were temporarily unavailable for download but were later restored. No books were deleted from users' devices.

In October 2012, Amazon suspended the account of a woman in Norway who bought a Kindle in the United Kingdom. Amazon deleted all e-books on her device but did not explain why. After she told the media, Amazon restored her account and the books.

Richard Stallman, a computer programmer, criticized the Kindle, saying Amazon's rules allowed the company to delete books, require users to share personal information, and limit choices for independent book sellers.

Since 2012, Amazon sold e-books in China and began selling Kindles there in 2013. Amazon said it sold millions of Kindles in China, where it became the largest market for the device in 2016. However, Chinese users preferred smartphones for reading, even with competition from companies like Tencent and Alibaba. Local brands like Xiaomi and Onyx Boox also competed with the Kindle. In 2022, Amazon stopped selling Kindles in China and said its online bookstore would close in June 2023.

On January 4, 2022, Amazon reported a shortage of Kindles on its JD.com store. Only the Kindle 10 model was available, while other models were out of stock. Amazon also closed its Tmall and Taobao stores, leading to rumors that Amazon was leaving China. An Amazon representative said the company still wanted to serve Chinese customers and that Kindles could still be bought through other stores.

In June 2022, Amazon announced it would close its Kindle bookstore in China, ending online book sales in the country starting July 2023. Existing customers could still download books they had already bought until June 2024.

Also in June 2022, self-published authors protested Amazon's e-book return policy. When customers returned e-books, Amazon took money from the authors' earnings, sometimes leaving them with negative balances.