Before we jump in, let's break down exactly which iPads we're going to be looking at:
- iPad Air 2
- iPad Air
- 4th-gen iPad
- 3rd-gen iPad
- iPad 2
For each category you'll see two rows of images, ordered exactly as they are in the list above. If you lose track, just hop back up here.
If you aren't sure which iPad you already have, just find its model number (written in tiny text near the bottom of the tablet's back) and check it against this list.
Forget how long you've had your current iPad? Or maybe you had no idea that your iPad 2 first launched three-and-a-half years ago? These are the dates that each tablet originally released.
The first four iPads had similar heights and widths, but varying thickness. Then with last year's iPad Air, Apple gave the product a makeover, with a narrower face and dramatically thinner build.
This year's iPad Air 2 takes things even farther, with an insane 6.1 mm (0.24-in) thickness. That's 19 percent thinner than last year's model.
We see a similar trend with weight: the first four iPads were relatively hefty, but then the iPad Air turned a corner. And the iPad Air 2 is 7 percent lighter than last year's Air.
You won't see any plastic on Apple tablets, as all six iPads have aluminum unibody constructions.
The iPad Air 2 is the first to come in more than two color options. You can now buy it in the same three hues as you can the latest iPhones.
If this post's title didn't spoil it for you, all six full-sized iPads have 9.7-in screens. They also all share the same 4:3 aspect ratio.
In early 2012, the iPad's display quality took a big leap forward with the first iPad Retina Display. It packs in 4x the pixels of either of the first two iPads.
Apple hasn't changed the resolution since then, but the company says that the iPad Air 2 has greater contrast and better viewing angles.
The iPad Air 2 is also Apple's first tablet to have an anti-glare coating on its display. Apple says it can reduce glare by 56 percent.
The iPad Air 2 and iPad mini 3 both have Apple's Touch ID sensor in place of the old home button. It lets you easily secure your tablet and log into Touch ID-enabled apps.
Touch ID also lets you pay with the online portion of Apple Pay. As for the physical (in-store) portion, you'll need an iPhone 6 or 6 Plus, or the upcoming Apple Watch.
The iPad Air 2 follows the iPhones 6 and 6 Plus in skipping the 32 GB storage tier, and jumping straight to 64 GB.
As you might expect, each new iPad was faster than its predecessors. The last two iPads have 64-bit architecture, which moves the tablets' foundations closer to that of desktop PCs.
The 2 GB of RAM in the iPad Air 2 should be a nice upgrade. After returning from another app or tab in the iPad Air 1, I find browser tabs needing to reload more often than I'd like.
The last three 9.7-in iPads have moved to Apple's smaller and reversible Lightning connector. The older iPads used the big 30-pin cables, which you can trace all the way back to some of the early iPods.
In the name of thinness, Apple cut the side switch from the iPad Air 2. In the older models, it could be used to either lock the screen's orientation or mute audio.
All of the iPads were originally sold in either Wi-Fi only or Wi-Fi with cellular models, but only the last four have supported LTE.
With the iPad Air 2, Apple is dropping a bomb on the wireless carriers with the Apple SIM. This customer-friendly card lets you switch among carriers (in the US and UK only) without changing SIMs. Of course you have to be using a more expensive cellular-enabled iPad though.
The batteries in the newer models might look weaker, but, thanks to more power-efficient processing, all the iPads should have roughly the same battery life (Apple originally advertised the same "up to 10 hours of web surfing over Wi-Fi" in every model).
Apple didn't add Siri to the iPad until iOS 5 arrived on the 3rd-gen model. Jailbreakers have proven that the voice assistant can run on the iPads 1 and 2 without a hitch, but Apple chose not to include it (perhaps as an incentive to upgrade?).
Smart Cover support
The original iPad doesn't have the internal magnets needed to use Apple (or third-party) Smart Covers. You know, the ones that automatically turn your screen off when the cover is closed, and vice versa.
Even the three-and-a-half-year-old iPad 2 received the big iOS 8 update in September. The original iPad is stuck on iOS 5.1.1 – from way back in May of 2012.
Starting price (current)
All of these iPads originally started at US$500 for 16 GB and Wi-Fi only. Today only the iPad Airs are still officially available (though you can probably still find the iPad 4 for a little while, until retailers clear out their stock).
Upgrade time?If you own an iPad from 2012 or earlier, even last year's iPad Air will be a big step up from what you have right now. And its new $400 price tag makes it the best deal on a discounted (year-old) iPad yet.
But the iPad Air 2, while not a dramatic upgrade, is a bigger update than you might think. You can hit up our full iPad Air 2 review for more.
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