Amazon has announced a refresh for its standard Kindle model. It has introduced a new Kindle Kids, too.

The new 6-inch Amazon Kindle comes with an improved display - it gets a significant resolution bump to 300ppi. It is also the lightest, most compact Kindle device yet and comes with a USB-C port for charging.

Battery life has been improved too, with Amazon claiming that it now lasts up to six weeks between charges. And finally, the storage has been doubled to 16GB. That is capable of housing thousands of eBooks and magazines.

There is a built-in adjustable front light, while dark mode is also supported on the new device.

The new Kindle Kids version is the same in specifications but comes with a Kid friendly cover included. It includes a one-year subscription to Kindle Kids for unlimited access to thousands of age appropriate eBooks, plus a two-year worry-free guarantee whereby Amazon will replace it if broken.

"With a high-resolution display that delivers three-times more pixels than our previous base Kindle, USB-C charging, 16GB of storage, and built-in adjustable front light, the new ultralight Kindle is the latest example of how we continue to bring premium features to our entry-level devices for even more customers to enjoy," said the vice president of Amazon Devices and Services, Kevin Keith.

"And since we launched Kindle Kids three years ago, kids have logged nearly three billion minutes reading on Kindle devices. The new Kindle Kids provides an even better reading experience to help kids become lifelong readers."

Both the new Amazon Kindle and Kindle Kids are available to pre-order in the US and UK now for shipping in October.

The Amazon Kindle starts at $99.99 / £84.99 in black or "denim" colours. The Kindle Kids is $119.99 / £104.99 for a black version, but there is a choice of Space Whale, Unicorn Valley, and Ocean Explorer cover designs.