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LG G Flex (Sprint) Review

Our Verdict

A head-turning flexible design and vibrant display make the G Flex an exciting Android device, but it's not our favorite phablet.


  • Durable flexible design
  • Vivid color screen
  • Solid battery life
  • Sharp camera


  • Poor speaker quality
  • Inconvenient rear key design
  • Lower resolution than other flagship phones
  • Pricey

The feature list for the LG Flex reads like a superhero character cocktail. This Android phone reminds us of Plastic Man, sporting a curved display and bendable design that can withstand up to 80 pounds of pressure without cracking. It's also like Wolverine, with a polymer back that heals itself from some minor scratches. However, at $299 on Sprint, this pricey 6-inch Android handset is also Hulk-like in terms of its size. Is the LG G Flex the shape of things to come in the smartphone world or just a gadget full of gimmicks?

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If Salvador Dali designed a smartphone, it would look just like the LG G Flex. With a body that dips ever-so-slightly in the middle, the G Flex looks at first glance like it was bent out of shape by accident. Having that bow in the middle allows the phone to flatten a little when you apply extreme pressure to its backside. LG claims that the G Flex can survive up to 80 pounds of force and, indeed, the screen did not crack even when our 180- pound co-worker placed it in his back pocket and sat on it or pushed down on it hard with his hand. 

The curved shape of the phone also made it feel slightly more natural to hold against our face than a typical flat phone. However, the extreme length of the phone makes it unlikely most people would hold it against their ears for a long time and, in all the years we've been using smartphones, we've never complained that they were too parallel to our cheek.

At 6.3 x 3.2 x 0.34 inches and 6.2 ounces, the LG G Flex is one of the bulkier phones on the market, easily dwarfing the 5.7-inch Samsung Galaxy Note 3 (5.95 x 3.12 x 0.33 inches, 5.9 ounces). However, the HTC One Maxx (6.5 x 3.2 x 0.41 inches, 7.7 ounces) is even bigger and heavier despite its smaller 5.9-inch display. The 6.3-inch Samsung Galax Mega is also larger (6.6 x 3.5 x 0.3 inches, 7 ounces).

Click to EnlargeThe G Flex's dull gray, glossy plastic body is nothing to text home about.

The back also doesn't shun fingerprints, which are even more prominent on the front bezel. Like the LG G2, the G Flex uses a Rear Key power button and volume rocker that's located in the middle of the back instead of on the sides. We found it hard to get used to feeling for the power button with our index finger rather than pressing it with our thumb, but some users may prefer this novel placement.

Despite having a slightly thicker bottom bezel than the Galaxy Note 3, the G Flex has software navigation buttons that eat up 78 pixels of screen real estate rather than the hardware buttons Samsung and HTC use on their phones. Unfortunately, LG does not allow you to swap out the battery or add a microSD card for memory expansion.

Self-Healing Back

Click to EnlargeLG claims that the backside can heal from minor scratches such as those that come from brushing against the keys in your pocket. When we scraped the back lightly with a penny, the minor scratches we created faded within seconds. However, three slightly deeper scratches we created near the rear key remained unhealed even after three days. On the bright side, because the back is so glossy and has a striped texture, it was hard for us to see any scratches without shining light directly on the back and looking very closely.

Display and Audio

Click to EnlargeThe LG G Flex's 6-inch, 720p display provided some of the most vibrant, accurate color we've seen on a smartphone. Thanks to LG's Real RGB technology, which optimizes subpixel alignment, images were even more attractive than on the Samsung Galaxy Note 3 and its 1920 x 1080 display. At 445 lux on our light meter, the G Flex sits well above the 406 lux smartphone category average and about on a par with the HTC One Max (441 lux), but it falls below the Galaxy Note 3's 550 lux measurement.

When we played a 1080p trailer for "The Avengers," images had more of a yellow cast on the Galaxy Note 3, while LG's representation seemed more true-to-life. When we viewed the same Web page on both devices, the white background behind an article was a pure white on the G Flex, but a bit yellowed on the Galaxy Note 3. However, due to its higher pixel density and hardware navigation buttons, the Note 3 showed about three more lines of text on the screen at a time in portrait mode.

The back-facing speaker on the G Flex doesn't rock. At 78 dB on the Laptop Mag Audio Test, the G Flex is quieter than the 80 dB smartphone category average and even quieter if you accidentally muffle the speaker with a finger while holding it. However, you won't want the volume too loud when you hear its tinny, unpleasant output. Whether we played the R&B classic "Forget Me Nots," the drums section sounded like a person rolling fingers on foil. Metallica's heavy metal "Enter Sandman" was even worse, with a guitar that sounded more like a jackhammer.


Click to EnlargeThe G Flex sports LG's heavily skinned version of Android 4.2.2 and provides a few attractive visual enhancements and some additional functionality over Google's stock interface. The lock screen has room for up to five shortcuts, though it comes blank by default. Tilting the phone pans around the lock screen's wallpaper using a feature called Swing Lock Screen, giving you a different angle on the nature scene it shows. Swiping to the right brings up the camera for quick photos. Pulling the two sides of the lock screen apart from the middle launches a media menu with quick access to photos, videos and music files.

MORE: 12 Surprising Things Your Android Phone Can Do

If reaching the rear power button is too much of a hassle, you can wake the phone or put it to sleep by double-tapping on the screen. LG calls this feature "Knock On," and we found it much more convenient than using the rear key.

Like other LG phones and those of many competitors, the G Flex has an extensive quick settings menu in its notification drawer. From there you can toggle the Wi-Fi, Bluetooth, Audio, NFC and many other simple functions. You can also open the Q Slide menu, which allows you to launch up to two of 10 different apps in floating windows on the desktop, making multitasking easier. We appreciated being able to float the calculator and notes apps on top of our screen, but were disappointed that there was no floating browser or media player.

Click to EnlargeJust like Samsung Galaxy phones, the Flex also offers a split-screen mode that lets you divide the display evenly between two apps. To enable split screen, we simply held down the back button, after which we were presented with a list of 14 compatible apps. Options range from the Chrome browser to the Gallery, YouTube, Gmail and Google apps. We could then drag an icon off the menu to open its app on the screen. If another compatible app was already in the foreground, the screen would split between the two. We particularly liked having Gmail and the Chrome browser next to each other because it let us browse the Web and our inbox at the same time.

LG's Slide Aside feature provides an interesting way of switching between open apps. You can swipe to the left with three fingers to dock an open app and then slide to the right with three fingers to bring it back on screen again. You can dock up to three apps at once this way, but we found using the standard Android task switcher (available by holding down the home button) easier to use.

One of LG's most useful custom features is Guest mode, which allows you to create limited accounts for other people who use your phone. In the settings menu, we created a guest account that had its own unlock pattern and access to only those apps we selected, which in our case was just the Chrome browser. After locking the phone and unlocking it with the guest pattern, we had access only to the app we had designated.


LG's virtual keyboard provides a slew of helpful features, including the ability to enable/disable a number row, next-word prediction and a handwriting recognition mode. We particularly appreciated being able to switch between regular and split keyboard mode just by pinching. However, we wish the optional haptic feedback was stronger; even on its highest mode, we could barely feel it. The G Flex also comes with Swype, which lets you type by tracing between letters on the keyboard.

Remote Control

Like the LG G2 and the LG G Pro before it, the G Flex has an infrared port and QuickRemote software you can use to control your TV, cable box, DVD player and other home theater equipment. Setting up the software to work with our LG TV was a snap, and it also works with all the major TV brands. However, we were disappointed to find that the app still doesn't have a program guide like Samsung's WatchOn software.


Click to EnlargeBecause of its quad-core Qualcomm Snapdragon 800 processor and 2GB of RAM, the LG G Flex offers speedy performance that's about on par with or better than most high-end smartphones on the market. Whether we were surfing the Web, Jetskiing around the track in Riptide GP 2 or playing HD videos, our experience was always smooth and lag-free.

On Geekbench 3, a synthetic benchmark that measures overall performance, the LG G Flex 2 scored a healthy 2,183, which is comfortably above the 1,664 category average and the Snapdragon 600-powered HTC One Max's mark of 1,902. However, the Samsung Galaxy Note, which has the same Snapdragon 800 CPU but comes with 3GB of RAM, notched a higher 2,983.

When we used VidTrim to convert a 204MB, 1080p video to 480p, the LG G Flex completed the task in a solid 7 minutes and 3 seconds, much faster than the 8:15 category average and the HTC One Max's mark of 7:33. However, the Galaxy Note 3 completed this task in a mere 6:12.

On An3DBench, a synthetic benchmark that measures graphics prowess, the G Flex scored a solid 7,584, which beats the category average of 7,433 but falls short of the Galaxy Note 3 (7,828).

Sprint Spark LTE Performance

Click to EnlargeThe LG G Flex is one of a handful of phones that support Sprint's new Spark network, which promises faster speeds than its regular 4G LTE signals. Unfortunately, Sprint's connection was really weak in a few prominent areas where we tested. In Manhattan's Flatiron district, we stood in several locations, including right in front of a Sprint store, and were barely able to hold a signal as the bars cycled between 1 and 3 with the Spark logo on most of the time. In the neighborhood, we achieved an average download speed of 3 Mbps and uploads of 0.7 Mbps, which is barely faster than 3G speeds. In our East Side apartment, we got a more consistent 3 bars and Spark connection but speeds were still poor with average speeds of 3.9 Mbps down and 1.7 Mbps up.

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When we sat in front of the East River, we finally got a really strong signal, which gave us average download speeds of 25.4 Mbps and upload speeds of 2.9 Mbps. By comparison, the Sprint Galaxy Note 3, which does not have Spark compatibility, averaged 8.46 Mbps down and 6.41 Mbps up in its best location.


With its 13-MP rear-facing camera, the LG G Flex provides sharp, colorful photos that are competitive with the best handsets on the market, including the iPhone 5s and Samsung Galaxy Note 3. When we shot a picture of the Empire State Building with all three phones, all three provided stunning output, but we found the colors a bit more vibrant on the iPhone and the Note 3. On the plus side, details were sharper on the G Flex than on the 8-MP iPhone.

The G Flex has its fair share of special camera modes. Dual camera mode lets you shoot with both the front 2.1-MP camera and the rear 13-MP shooter at the same time, imposing a little box with your face on top of the picture. Shot & Clear removes people who walk through your shot, just like Samsung's Eraser Mode. Our favorite camera feature, Time Catch shot, allows you to retrieve five photos from before you hit the shutter button, making it easy to retrieve that moment when your toddler was doing something cute. Samsung offers even more camera features, but we like what the G Flex offers.

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The LG G Flex shoots video that looks as good as its stills. When we captured a 1080p clip of cars rolling down a New York City street, the outlines of cars and buildings were particularly crisp. However, colors were more muted than on the Galaxy Note 3 as a red billboard appeared reddish brown on the G Flex but bright red on Samsung's phone.

Battery Life

With its 3,500 mAh battery, Sprint's version of the LG G Flex lasted exactly 8 hours on the LAPTOP Battery Test, which involves continuous surfing over 4G. That runtime is far better than the smartphone category average of 6:44. However, the T-Mobile version of the G Flex endured for a full 11:25 on the same test, and the AT&T version lasted 9:33. On Sprint, the Galaxy Note 3 lasted a stronger 8 hours and 48 minutes and the HTC One Max lasted 8:33.

MORE: 10 Smartphones with the Longest Battery Life


LG preloads the G Flex with several useful proprietary applications and a few we could do without. Like most phone vendors, LG provides its own versions of the Android alarm clock, calculator, calendar, gallery and non-Gmail email client. LG's Memo allows you to write quick post-its, Notebook is for longer notes, but limited options make it feel like a stripped down version of Samsung's S-Note. Voice Mate accepts voice commands, allowing you to make calls, compose emails, read SMS messages and more.

MORE: 25 Best Android Apps

Click to EnlargeVideo Editor lets you create your own movies, using video, image and audio files, while Voice Recorder captures sound. LG Backup keeps your data safe. Life Square keeps a log of all your activities -- taking photos, making calls, etc. -- so you can remember what you did. We particularly appreciated LG's Quick Translate app, which translates foreign-language text in real-time when you point the camera at signs, books, menus or labels. LG also throws in its own Web browser, but we prefer Google Chrome (also preloaded).

Unfortunately, Sprint also throws on its fair share of carrier-branded bloatware. Sprint ID allows you to switch between themed sets of recommended apps. Sprint Money Express allows you to manage a prepaid credit card. Sprint TV & Movies provides access to a handful of free video clips and the option to subscribe to channels for prices ranging from $2.99 to $.7.99 a month. Fortunately, some of the third-party apps, which include a CBS sports app, 1Weather and eBay, can be uninstalled. About the only useful Sprint app is Sprint Zone, which lets you access account information (along with news and recommended apps).


Click to EnlargeThe G Flex is an Android flagship phone that desperately wants your attention. And this device grabs it with a unique curved screen and "self- healing" back. But while LG has certainly innovated in the design department, you still have to deal with the cumbersome Rear Key placement. If you put the special features aside, you're left with a device that offers a beautiful (albeit lower-res) display, strong performance, solid battery life and a sharp camera.

If you want better built-in software, even more speed and longer endurance on Sprint, consider spending $50 extra on the $349 Samsung Galaxy Note 3, which is not Spark-compatible. Willing to consider another carrier? The LG G Flex on T-Mobile offered 3 more hours of battery life in our tests. However, if you want a high-end phone on Sprint with faster Spark data speeds and are intrigued by its curves, the G Flex is a good choice.

Tech Specs

Alternate CarriersT-Mobile, AT&T
Bluetooth TypeBluetooth 4.0
BrandLG Electronics
CPU2.26-GHz quad-core Qualcomm Snapdragon 800 processor
Camera Resolution13MP
Display (main)6-inch 1280 x 720 P-OLED display
Display Resolution1280x720
Form FactorCandybar Touchscreen
Front Camera Resolution2.1MP
Internal Memory32GB
Memory Expansion TypeN/A
OS FamilyAndroid
Operating SystemAndroid 4.2.2
Phone Display Size6
PortsmicroUSB, 3.5mm headphone
Processor FamilyQualcomm Snapdragon 800
Size6.3 x 3.2 x 0.31 - 0.34 inches
Weight6.2 ounces
Wi-Fi802.11 a/b/g/n/ac