The Kindle Fire and Kindle Fire HD have gone on sale in the UK, marking the first time Amazon has launched tablets in the country.
The company began shipping the tablets and its new Kindle Paperwhite e-reader on Thursday, after opening pre-orders two weeks ago. All of the devices were already available in the US, and in the case of the Kindle Fire, have been out for a year.
The Kindle Fire tablets go up against Google's Nexus 7 and the newly arrived Apple iPad mini in the chase for Christmas shoppers. With the Paperwhite, Amazon is looking to build on the success of its other popular e-readers.
"Kindle Fire HD is our most advanced seven-inch tablet and is already the bestselling product for Amazon worldwide. Kindle Paperwhite is the e-reader we always wanted to build and pre-orders have exceeded all expectations," Jorrit Van der Meulen, head of Kindle in Europe for Amazon, said in a statement.
The Android-based Kindle Fire HD comes in 16GB (£159) and 32GB (£200) models. Google's two Nexus 7 models cost the same, but have only 8GB and 16GB of storage respectively. Amazon's 8GB seven-inch tablet, the Kindle Fire, costs £129.
All are considerably cheaper than Apple's iPad mini, which will cost £269 for a 16GB version and £349 for a 32GB version when it hits store shelves on 2 November. However, it does offer more on-board storage than its rivals, providing 64GB for £369. It also has the option of cellular connectivity, unlike the others, which are Wi-Fi only for now - though a cellular Nexus 7 is rumoured to be coming at a Google event on Monday.
Chief executive Jeff Bezos has said Amazon is not making a profit on its devices, as it is selling them at cost. Its strategy is to sell cheap and rely on sales of apps and services delivered onto the hardware and make its profit there - something analysts have applauded.
The Kindle Fire HD has a 1,280x800-pixel display and a 1.2Ghz OMAP 4460 processor that means it is 40 percent faster than the original Kindle Fire, according to Amazon.
Meanwhile, the Kindle Paperwhite costs £109 for a Wi-Fi-only version. With 3G connectivity added, the price rises to £169.
The tablets and e-readers are available from high street retailers such as Currys, Tesco and John Lewis, as well as from Amazon's own e-retail site.