How Does Kindle Work? What to Know in 2024

The original Kindle had an off-white plastic casing and an asymmetric, beveled shape, like a closed three-ring binder. It was 7.5 inches (19 centimeters) long and 5.3 inches (13.5 centimeters) wide, only 0.7 inches (1.8 centimeters) thick and weighed a mere 10.3 ounces.

Since then, Amazon has released many generations and several versions of its popular e-reader.

Kindle Sizes

The 11th generation Kindle, released in 2022, has a 6-inch (15-centimeter) display and is 6.2 inches (16 centimeters) long, 4.3 inches (11 centimeters) wide and 0.32 inches (8 millimeters) thick. It weighs 5.56 ounces (158 grams).

The largest model in the lineup, the e-reader/digital notebook Kindle Scribe, has a 10.2-inch (26-centimeter) display and is 9.0 inches (230 centimeters) long, 7.7 inches (196 centimeters) wide and 0.22 inches (5.6 millimeters) thick. It weighs 15.3 ounces (433 grams).

The Paperwhite was released in October 2012, and is in its 11th generation as of 2024 (it was released in 2021). It measures 6.6 inches long by 4.6 inches wide by 0.3 inches thick (167 millimeters by 113 millimeters by 8.2 millimeters).

Kindle Screen

The central feature on all the Kindle models is the electronic paper screen. The Kindle Paperwhite gets its name from its display, which is whiter than the base Kindle display. The lighter screen gives more contrast with the text, making it easier to read than the light gray color of the Kindle's screen.

All Kindle screens can display images in 16 levels of gray using electronic ink technology. Unlike LCD screens, the Kindle e-reader's screens aren't backlit.

The crispness of the electronic ink screens makes them much easier to read in direct sunlight than devices with color LCD screens. The earliest Kindles required you to use a flashlight if you wanted to read in the dark, but now all of Amazon's e-readers have front-lit screens.

A thin sheet of nano-imprinted flattened fiber optic cable distributes the light uniformly over the entire screen, giving the illusion that it is backlit. But since the light is directed toward the screen and not toward your eyes, the Kindle retains its electronic ink advantage of being easy to read.

Despite the addition of light, which is usually a big power drain, Kindles keep battery usage at a minimum by using low-powered LEDs as the light source. The basic Kindle uses four LED lights, the Paperwhite has 17, and the Scribe has 35.

At its most basic level, the Kindle is just a specialized portable computer. It has many of the bits and pieces you'd expect to find in any computing system. It also has a couple of elements that set it apart from your average computer.

Circuit Board

Most of the Kindle's components attach directly to a circuit board. The circuit board acts as the foundation for electronic circuits in the Kindle. Most of the components are inseparable from the board. The various chips on the board include the processor, memory, USB connector and touch screen interface.

Battery

The Kindle draws its power from a rechargeable lithium-polymer battery.

According to Amazon, the battery in the base Kindle can last up to six weeks without recharging, and the batteries in the Paperwhite may last up to 10 weeks.

The Kindle Scribe has a battery life of up to 12 weeks of reading or three weeks of writing. Actual battery life depends on how much you use the light, wireless and Bluetooth.

Operating System

All versions of the Kindle use a Linux-based operating system. According to hardware hacker Igor Skochinsky, it uses the Das U-Boot bootloader to initialize its OS.

One complaint some people had about early e-book readers was that they found it difficult to read words on an LCD display. Some users complained that longer reading sessions put too much strain on their eyes.

Amazon's solution to this problem was to use electronic ink technology. The Kindle's electronic ink screen looks more like paper than an LCD screen. It reflects light in much the same way that paper does.

How Electronic Ink Technology Works

A company called E Ink in Cambridge, Massachusetts, developed the technology the Kindle relies upon to display text and images. Rather than use the liquid crystals you'd find in an LCD or the ionized gas you'd find in a plasma display, electronic ink actually uses millions of microcapsules, each only a few microns wide.

Each microcapsule contains a clear fluid and thousands of white and black particles. The white particles carry a positive magnetic charge, and the black particles have a negative charge.

It's these positively and negatively charged particles inside the microcapsules that make electronic ink displays possible. An array of thousands of tiny electrodes lies beneath the electronic ink display.

When an electrode emits a negative charge, it repels the negatively charged black balls, pushing them to the top of the microcapsule. At the same time, the negative charge attracts the positively charged white particles to the bottom of the microcapsule. When the electrode emits a positive charge, the white and black particles switch places and the screen appears to be blank.

Working together, thousands of electrodes and millions of microcapsules generate the text and images you can see on an electronic ink display. Through precise charges the Kindle can display a range of grays to provide shading in images.

You can even also the Kindle's font settings to display text in a larger or smaller font size. The Kindle's electronic ink screens can also render images but having only 16 shades of gray limits the detail of any pictures.

E Ink now makes color versions of its displays, but as of 2024 none of Amazon's readers use it. The Kindle Fire tablet — Amazon's color version of the e-reader — is backlit like other tablets.

Energy Usage

The Kindle uses less energy to generate a page view than a comparable LCD or plasma screen because it pulls power from its battery only during the initial page generation. Once the image is on the page it can stay there without requiring electricity.

It doesn't require more power until the user "turns" the page. This feature is what lets the Kindle's battery provide power for weeks at a time on a single charge.

The Amazon Kindle gives you wireless access to an electronic store that includes millions of books, newspapers and magazines.

The Kindle allows you to buy books directly from the device. Alternately, you can browse books in the Kindle store using on another device and Amazon will send the electronic books directly to your device.

File Types

The files you access with a Kindle are in a proprietary format with the extensions AZW, AZW1, AZW2 or AZW3. These files include digital rights management (DRM) that prevents you from sharing your files with other users.

Kindles can handle Audible files (.aax) files, but not MP3s. Amazon also can convert several other types of files into the AZW format so that the Kindle can read them. These file types include:

Each Kindle has a unique email address. You can send compatible files to your Kindle by e-mailing them as an attachment to this address. You can also connect your Kindle to a computer with the USB cord to transfer files.

Cloud Storage

Every purchase you make from Amazon goes into a special folder called your library. Amazon uses a cloud storage model where the file lives on one of Amazon's computer servers.

That means even if you delete a book from your Kindle device to conserve space, the record of your purchase will still exist in your Kindle library on Amazon's servers. You can download the book again to your Kindle for no additional charge.

There are also free Kindle reading apps for many devices, including iPhone, iPad, Android devices and Mac and Windows-based computers, so that you can buy and read Kindle books without purchasing a Kindle.

One advantage to all the available apps is that you can partake of Amazon's Whispersync technology, which synchronizes the last page you read on one device across all your Kindle readers, including your physical Kindle if you have one or more, so that you can read on multiple devices without losing your page when you switch.

There are also libraries of free e-books available online, many of which are in the public domain. And many public libraries let you check out e-books and read them with your Kindle; Libby is a free app you can use to find and borrow library books for Kindle.

Deregistration

What if you've lost your Kindle, or some unscrupulous person has taken a kindled interest in it and stolen it from you?

You should go to your Amazon profile and deregister your Kindle as soon as possible. Otherwise, the thief may use your Kindle to download a library of books on your dime.

Upon its debut, the Amazon Kindle costed $399. While some critics said the price tag was too high, the demand for the Kindle soon depleted Amazon's stock of the device.

Amazon's CEO Jeff Bezos offered an apology to customers. He claimed that the company sold out of its stock in less than six hours. Some bloggers suggested that Bezos' goal wasn't to offer a sincere apology — it was to drive up more interest for the device.

When the Kindle became available again, the price dropped to $359. Amazon didn't release sales numbers to the public, leaving many to question exactly how popular the device was. It seemed like the Kindle belonged to the realm of folklore — you didn't own one, but a friend of a friend did.

Kindle and Oprah

Amazon got a huge publicity boost in October 2008 when Oprah Winfrey named the Kindle as her favorite gadget. Oprah devoted most of an episode of her show to promoting the Kindle. She invited Jeff Bezos to the show to talk about the device, explaining its features to her audience.

Oprah also announced an electronic coupon for the device. Nowadays the entry-level Kindle can be had for less than $100.

Criticism

Kindle readers usually rank at the top in journalists' lists of best readers. Amazon's advantages help fuel this, especially against other companies with similarly equipped e-readers.

But the company hasn't been free of criticism, and the integrated bookstore is often a topic of complaint.

Electronic copies of books sometimes cost about half as much as physical copies, something that seems unfair to some people. Unlike a physical book, there are very few production and distribution costs associated with an electronic file.

Amazon also got into hot water when it remotely deleted copies of George Orwell's "1984" and "Animal Farm" stored on customers' Kindles. It turns out the publisher that made the books available didn't have the proper rights. Amazon credited customers the money they spent on the books and apologized for the situation.

The incident brought to light a potential problem with electronic copies of books: a gray area for consumers when it comes to owning digital information. Turns out these companies doesn't own these e-books, they license them.

If something happened to the company you bought these books from, the content would no longer be available to you. You also can't read an e-book you bought via Amazon Kindle on a rival e-reader like Nook [source: Warner].

In 2012, Amazon was accused of terminating a woman's account and deleting the books from her device, stating that her account was linked to another that had abused its policies. The company didn't provide much information and gave no recourse for resolution. While this is one isolated incident, it prompted renewed concern about digital rights management (DRM) [sources: Aguilar, Mosbergen].