Kindle Fire HD vs Kindle Fire HD 8.9: what is Kindle Fire HD?
Both the original Amazon Kindle Fire HD and the Kindle Fire HD 8.9 are grown up e-readers that are also great for watching movies and films, browsing the web, sending and receiving email and playing games. You can download and install apps and music, and - yes - read books.
Indeed, with its heavily customised version of Android the Kindle Fire HD is a well-priced full-blown tablet, albeit an Android tablet that is tied in to Amazon's world. You can buy books, music, games, apps and movies to your heart's content - but you have to buy them from Amazon. That's not a problem. Amazon is, after all, pretty well stocked on that score. But it does illustrate the limitations of the Kindle Fire model. If Amazon doesn't want you to install it, you can't install it.
There are benefits to this: both the original Kindle Fire HD and the Kindle Fire HD 8.9 share an easy-to-use interface. They are entertainment devices designed to be used by just about anybody - regardless of their technical knowledge.
As you might expect finding and reading books using the Kindle Fire HD and Kindle Fire HD 8.9 is a great experience, even allowing for the extra weight. But you will find some limitations. You can install third-party apps, for instance, but it requires some technical knowledge to run apps from outside of Amazon's own app store. So although you can watch BBC TV programs on BBC iPlayer, ITV Player and 4oD remain conspicuous by their absence.
Movies is another area in which the Kindle Fire HD and Kindle Fire HD 8.9 are slightly hobbled. Amazon wants you to use Lovefilm Instant for movies. To access this you need to sign up for a monthly subscription. That's all well and good, but it is an extra expense and to use Lovefilm you have to be online (you can't download films to your device). You can also install the Netflix app and sign up for that service.
And even the web-browsing experience is far from perfect. There's no general support for Flash, which means some websites don't work perfectly. Amazon has now included a Flash video player, however, so you can watch video clips embedded on websites. See also Group test: what's the best cheap tablet PC?
Kindle Fire HD vs Kindle Fire HD 8.9: design and build
The Kindle Fire HD 8.9 shares almost identical design and build quality with the original Kindle Fire HD - it is simply stretched to incorporate a bigger screen. So where the original Kindle Fire HD (and the originial Kindle Fire, for that matter) sports a 7in display, the newer Kindle Fire HD has an 8.9in screen. In both cases the screen is designed to be used in landscape format for everything but reading books. You get a shiny black slab with a capacitative touchscreen taking up most of the front.
Build quality is similar: Kindle Fire HD tablets are designed to be used often and on the move, and to sell at a cheap price. So they are robust and built to last but lack a little of the stylish finish of iPads or Nexus tablets. The bezel around the screen on both devices is thicker than we'd like, and at 567g the Kindle Fire HD 8.9 is a little heavy for a tablet. (Add in Amazon's well-designed case attached and you'll find yourself carrying around 785g.) If weight is an issue you could opt for the lighter Kindle Fire HD. Its 395g feels significantly lighter, especially when in use as an e-reader - try holding 567g in one hand as you read in bed. (For comparison the smallest Kindle e-reader weighs just 170g, but the Nexus 7 7in tablet is 340g. In my experience that is perfectly fine for reading e-books.)
This virtually identical design means both the Kindle Fire HD and Kindle Fire HD 8.9 sport similar ports, features and buttons in similar places. With either devive look on the bottom edge for micro-USB and micro-HDMI ports, and find the headphone jack sitting near the top. In both cases the two speakers are seated to the left and the right on the rear of the tablet, and the webcam is situated centrally above the screen. It does seem odd for an entertainment device to have rear-facing speakers, but the Kindle Fire HD and Kindle Fire HD 8.9 are hardly alone in that respect. And Amazon gets back its kudos for including the necessary cables and adaptors for synch/charge and TV output.
Both the Kindle Fire HD and Kindle Fire HD 8.9 hide their volume and power buttons on the right-hand side, flush with the tablet body. This can make them hard to find by touch alone. They also both suffer from a niggle with the keyboard in which the back button in the status bar sometimes sits to the right of the keyboard and you instinctively tap it to delete, instead of using the Delete key on the keyboard itself. See also: what's the best Android tablet?
Kindle Fire HD vs Kindle Fire HD 8.9: display
The first Kindle Fire HD has a 7in, 1280x800 10-point multitouch capacitive screen which uses an IPS LCD panel. That makes HD movies look good, with decent detail at a pixel-density level of 215ppi. One of the advantages of the Kindle Fire HD 8.9 is its excellent full HD screen. It has a resolution of 1920x1080 which means that it has a pixel density of 254ppi over a bigger area. In the case of both devices viewing angles are wide, colours are deep and contrast is good. But the 8.9in device makes up for its heavier weight with a bigger, more detailed screen.
Kindle Fire HD vs Kindle Fire HD 8.9: hardware and performance
Being blunt, the original Kindle Fire HD wasn't as fast as we'd have liked. In use it doesn't feel as snappy as an iPad mini or Nexus 7, especially when browsing the web or launching apps. Scrolling around web pages shows a white screen until the content is loaded.
The Kindle Fire HD 8.9 has a faster dual-core processor than the Kindle Fire HD but this doesn't make it feel noticeably zippier in general use. Both Kindle Fire HD devices trail the Nexus 7 in this respect, although the Kindle Fire HD 8.9 pretty much matches that tablet in our benchmarks.