We're not sure if it's a result of some holiday season generosity or some behind-closed-doors deal, but AT&T didn't mess around much with the Nokia Lumia 820. Sure, there's the usual carrier branding found on the front (its logo sits on the top-right corner, while Nokia's name is centered at the top), but you otherwise won't find any cosmetic differences. In terms of measurements, this weighs 0.07 ounce less than the global version (5.57 ounces vs 5.64) and is just a hair taller and thinner at 124 x 68.3 x 9.65mm (4.88 x 2.69 x 0.38 inches). We suspect this is only with the default back cover attached, which we'll discuss next, but we doubt that you'd notice it much even if you were to compare the two devices side by side.
By default, AT&T's unit comes with a plain black matte back cover that doesn't include contacts for wireless charging, but you can swap in a wide variety of shells in different colors (the red one is shown above), all of which are sold for $25 individually and are compatible with Qi's wireless charging standard. Fortunately, Nokia tells us that shells for the global 820 can be used, so feel free to buy yours through whatever channel you like.
Internally, you'll also find the specs to be the same: the phone sports a 4.3-inch, WVGA (800 x 480) ClearBlack OLED with 217 ppi; a 1.5GHz dual-core Snapdragon S4 Plus chipset; 8GB of internal storage; a microSD slot with support for 64GB cards; a 1,650mAh battery; a VGA-quality front-facing camera; and an 8MP rear cam with Carl Zeiss lens, f/2.2 aperture and 26mm focal length. It also houses quad-band GSM / EDGE and quad-band UMTS / HSPA+. The only change in the spec sheet is rather unsurprising: the device uses dual-band LTE that works on AT&T's 700MHz and AWS bands, instead of the penta-band LTE on the global version (none of those five bands are supported in the US).
When it comes to software, you'll get all of the usual AT&T suspects like Code Scanner, FamilyMap, Navigator, Radio, YPmobile and U-verse Live TV. All of these apps can be uninstalled, so there isn't much harm done if you find little to no use for them.
If there's one thing about a Windows Phone you can count on, it's reliable performance -- every WP8 device we've reviewed so far has impressed us with above-average battery life, processing power and internet browsing, and the AT&T-branded Lumia 820 is no different there. Since it uses the same dual-core Snapdragon S4 processor as the 920, it gets the job done just as well as the 920, offering smooth transitions, quick response and fast app load times. Here's what we found in our standard suite of benchmarks:
Oddly, the AT&T 820 didn't seem to fare as well as its global counterpart on the WPBench processor stress test, despite having essentially the same components. We're not terribly worried about a difference of 10 minutes, but it's still interesting to note nonetheless. As far as the important metric -- real-life use -- we got through the entire day with a little bit of juice left over. (Again, this is one of the major strengths of Windows Phone.) The 820 cranked out better results on WPBench and AnTuTu than both the Lumia 920 and the HTC Windows Phone 8X -- likely a consequence of using a smaller low-res display than the others. The speakerphone wasn't the loudest we've heard, but still sufficient for our needs; calls were unsurprisingly just as reliable as we found on the global 820.
At $50, the Lumia 820 is the least expensive Windows Phone 8 device you can buy on AT&T. While it makes for a perfectly reasonable budget phone, it's hard not to justify an additional $50 to grab the Lumia 920, which has a larger display with HD resolution, 32GB of storage, a better front-facing camera and optical image stabilization for improved videos and low-light photography. Fans of wireless charging will definitely want to go for the 920 -- once you throw in a Qi-compatible back cover and a charging plate, the 820 is actually more expensive than the 920, which includes both in its $100 cost. All told, we find it difficult to recommend the 820 over the 920; if you're going to be stuck with a phone for two years, you may as well pay a little more for the nicer of the two.