Amazon is reportedly planning a complete overhaul of its Kindle Fire tablets.

The online retailer will launch at least three brand new devices in the coming months ahead of the Christmas period, Digital Spy said citing BGR.

The first device will apparently be a replacement for the 7-inch Kindle Fire. A new panel will feature a higher resolution of 1,280 x 800 pixels - the same as Amazon's current Kindle Fire HD.

A new version of the Kindle Fire HD is also in the works, with an upgraded display featuring a 1,920 x 1,200-pixel resolution that remains 7 inches in size.

A new Kindle Fire HD 8.9 will see the resolution increased from 1,920 x 1,200 pixels to 2,560 x 1,600, according to the report, meaning it will have more pixels than Apple's 9.7-inch Retina display on a smaller 8.9-inch screen.

In terms of design, Amazon is apparently planning "big changes" for the new models, with a more angular design and corners that aren't as rounded.

The power and volume buttons will be moved to a sloping area on the case-back to avoid buttons being accidentally pressed when a tablet is placed on its back.

The new models are also said to be lighter, with pre-production models currently being tested for a possible September launch.