It's right up there with your wallet and keys, and it can sometimes even double as your wallet and keys. Your smartphone has become an indispensable companion, helping you stay on top of email and social updates, take and share photos and videos, play music and games, and do a whole lot more. So we probably don't have to tell you that choosing the right device is a big deal.
Our smartphone-buying guide covers everything you need to know before you buy, ranging from operating system and screen size to the camera and the carrier. Use this advice to make sure you get the very best handset for your needs and budget. Deciding between Apple's and Samsung's latest flagships? Check out our Galaxy S6 versus iPhone 6 face-off.
Operating System: Android, iOS or other?
Android dominates worldwide sales of smartphones, and for good reason. You'll find many more choices than iOS or Windows Phone when it comes to design, display size, specs, capabilities and price. Plus, Android is an open OS, which means it's easy to customize with widgets, launchers, your choice of keyboard and more. Some Android-phone makers, such as Samsung and LG, trick out the software with additional enhancements, such as more-robust multitasking and easier access to settings.
With the latest version of Android, 5.0 Lollipop, the OS offers a slicker and more intuitive design, improved quick settings, and Priority Mode for showing the notifications only from people who matter most. Plus, Android offers a huge number of apps in its Google Play store. However, when a new version of Android arrives, it can take a while for the updated OS to hit your phone.
The iPhone 6 and iPhone 6 Plus run the latest version of Apple's operating system, which offers all sorts of enhancements. You'll find an improved Photos app, interactive notifications and (finally) the ability to swap out your keyboard. Plus, Family Sharing lets up to six people in your family share iTunes, books and app purchases.
The biggest reason to opt for an iOS device is its selection of apps. Apple's App Store tends to get the hottest apps and games before Android, partly because developers have an easier time targeting a smaller set of devices that have similar specs. By the same token, iPhones enjoy the broadest array of accessories, because there's less variation in design from one model to the next.
Windows Phone has never caught on, but the upcoming Windows 10 could change that. Developers should be able to easily port Android and iOS apps to the platform. Windows Phone offers some compelling features on its own, such as a dynamic Start screen and the Cortana digital assistant, but they haven't been enough to sway shoppers.
Unless you're already a fan, don't touch this. The company formerly known as RIM has struggled to win over shoppers with BlackBerry 10. On the plus side, there's a Hub that aggregates everything from email to social updates in one place. It's also fairly easy to multitask on these phones, and you can get a physical keyboard from the BlackBerry Classic. However, the UI is not intuitive, and the app selection is pretty skimpy.
Although bigger screens are en vogue, you'll still find a wide variety of display sizes. And size is only part of the story.
Small Screen (Less Than 4.5 Inches)
The main reason to buy a small-screen smartphone is for its compact design. You won't have to stretch your thumb to reach anything. But this size range is falling out of favor as more and more people gravitate toward larger canvases for media consumption and gaming.
Medium Screen (4.5 to 5.4 Inches)
This has become the smartphone sweet spot, with such devices as the iPhone 6 (4.7 inches), HTC One M9 (5 inches) and Galaxy S6 (5.1 inches). Most phones are fairly comfortable to use with one hand in this category, depending on the button placement.
Large Screen/Phablet (5.5 Inches or More)
Smartphones with displays larger than 5.5 inches, such as the 5.5-inch iPhone 6 Plus and LG G4, and the 5.7-inch Galaxy Note 4, are often called phablets because they are tablet-like in size. These are more likely to be used as two-handed devices, but there are lots of people who prefer larger displays for watching videos, reading eBooks and even running two apps side by side, as you can on the Galaxy line.
Size and Weight
The weight of a smartphone is mostly dictated by its screen size. The 4.6-ounce iPhone 6, for example, has a 4.7-inch display and is one of the thinnest and lightest handsets on the market.
At the opposite end of the spectrum are big-screen phablets such as the Nexus 6, which has a 6-inch display and weighs 6.5 ounces. Once you get above 6 ounces, you'll really notice the weight of a phone in your pocket. If portability is paramount, shoot for a handset that's less than 5 ounces.
The size of the screen is only one consideration. Pay close attention to a smartphone's resolution, brightness, color quality and viewing angles.
Comparing displays of the Galaxy S6 (left) and iPhone 6 (right). The sharpest displays have quad-HD resolution, or 2,560 x 1,440 pixels, including the Galaxy S6 and LG G4. However, a full-HD panel, with 1,920 x 1,080 pixels (1080p), such as those on the iPhone 6 Plus and HTC One M9, shows plenty of detail. Screens with 1,280 x 720 pixels (720p), typically found on value-priced phones, can result in lost detail in text or movies.
Make sure that the smartphone you're shopping for has a panel that's bright enough you can read it outdoors in direct sunlight. (See the nit measurements in our reviews to compare.) Having wide viewing angles is important, too, because you'll want to be able to share what's on your screen with others and play games without the screen washing out when you tilt the device.
Our smartphone reviews include valuable test results on brightness, color gamut and color accuracy, to help you make the most informed buying decision.
Defining a good or bad smartphone design is highly subjective, but if you care about build quality and aesthetics, look for a unibody design, which you'll find on the iPhone 6, Galaxy S6 or HTC One M9. The S6's glass-and-metal design is particularly attractive, especially the S6 Edge with its dual curved display.
Left: LG G4 with a removable battery. Right: Apple's unibody iPhone 6.People who prefer a smartphone with a removable battery should opt for a device such as the LG G4 or Galaxy Note 4. The standard-issue plastic backs don't feel as premium, but you'll be able to swap in a new battery and upgrade the memory with ease.
If you're looking for a more personal design, check out the Moto X, which you can customize online with all sorts of colors and finishes, including wood. The LG G4 offers back covers in different styles, including leather.
We've now arrived at a point in smartphone evolution where the camera matters more than the processor, especially since most people use their phones as their primary shooters. More and more smartphones boast cameras with 16 megapixels, but don't go by numbers alone. Instead, pay attention to image quality, aperture, speed and features.
The iPhone 6 and 6 Plus, for example, have 8-MP sensors but capture relatively large pixels and accurate color. However, the Galaxy S6's 16-MP camera tends to offer more-saturated colors, better contrast and more detail, though it can blow out subjects in bright sunlight. Look at photo samples from Tom's Guide in our reviews and camera face-offs before you buy.
Also pay close attention to low-light photo quality. You should be able to get a decent shot indoors without using the flash. A larger aperture allows for this. For instance, the Galaxy S6 has an f/1.9 aperture and the LG G4 is rated for f/1.8, while the iPhone 6 is f/2.2. A lower number means a larger aperture, which typically translates to better low-light performance.
Comparing low-light indoor photos taken by the LG G4, Samsung Galaxy S6 and Apple iPhone 6 Plus.As far as camera features, look for optical image stabilization to reduce blur and improve low-light performance. Some phones, such as the G4, come with a wide range of manual camera settings for power users, such as white balance, manual focus, exposure and ISO.
Smartphone makers are also paying more attention to front-camera quality, as evidenced by such models as the HTC Desire Eye. Both the front and back shooters are 13 MP. The Galaxy S6's 5-MP camera takes sharp images and offers a wider-angle lens than the iPhone 6.
MORE: Best Smartphone Cameras
A good processor inside a phone should translate to faster open times for apps, smoother gameplay and quicker photo editing, but you don't have to pay attention to clock speed. It's better to look at the performance results in our reviews, such as Geekbench, which measures overall performance. Qualcomm's Snapdragon series used to be the fastest game in town, but now Samsung's own octa-core Exynos 7420 chip (inside the Galaxy S6) has taken the lead.
Among Qualcomm CPUs, the octa-core, 64-bit Snapdragon 810 processor (inside the HTC One M9) is the top-of-the-line processor. Meanwhile, the six-core Snapdragon 808 chip (inside the G4) is almost as capable, though the 810 has better graphics.
Apple's 64-bit, 20-nanometer A8 chip delivers smooth performance on the iPhone 6 and iPhone 6 Plus, enabling console-quality gaming (via Metal graphics). The A8 also comes with a new image-signal processor for better photos and videos.
The Snapdragon 600 series powers midtier smartphones, such as the Alcatel Onetouch Idol 3, and the 400 series is for low-tier or entry-level handsets.
Other CPU players include MediaTek, whose chips are often found on low- to mid-tier handsets.
Here's an easy way to look at smartphones' RAM, which is critical for multitasking. Try to avoid handsets with just 1GB of system memory. On midtier devices, 2GB is good and standard. But 3GB (found on phones like the Galaxy S6 and LG G4) is even better. Only one device (the Asus ZenFone 2) offers 4GB of RAM thus far, but it could be the start of a trend.
Given that some games can easily take up more than 1GB — not to mention how many high-res photos and videos smartphone owners are capturing — we highly recommend opting for as much internal storage as possible. The minimum on most handsets, like the iPhone 6, is 16GB, but more phones (such as the Galaxy S6) are coming standard with 32GB. We recommend 32GB or more.
A microSD card can help expand your storage. It's available on phones such as the HTC One M9 and LG G4, but keep in mind that microSD can often store only a portion of apps. These cards are better for storing media.
Many factors — including the screen size, processor and operating system — determine how long a smartphone lasts on a charge. However, shoppers looking for the longest battery life possible should check out our list of endurance champs. We consider any phone that lasts longer than 8 hours of straight 4G LTE surfing to be good, but greater than 8.5 hours is better.
Battery capacity is another spec that can help determine a phone's potential staying power, but be careful. In general, look for 2,600 mAh or more. Some examples include the Galaxy S5 (2,800 mAh) and Motorola Droid Turbo (3,900 mAh). But there are exceptions. The LG G3 3,000-mAh battery lasted only a little more than 7 hours on our tests, which we suspect was due to the resources required to power its sharp quad-HD display.
Removable batteries seem to be falling out of favor with most smartphone makers. But there are some benefits to this kind of design, found on the LG G4 and Galaxy Note 4. Once your existing battery stops holding a charge for as long as it did when it was fresh, you can just buy a new one without having to pay for a replacement service or new phone.
Third-party vendors, such as Mugen Power, make high-capacity replacement batteries that offer more endurance than the originals. Also, if you carry a spare battery, you'll be able to swap in a new one to keep your phone going longer.
Other Key Features
With myriad competing standards and a lack of direction from both smartphone makers and the carriers, wireless charging is more of a nice-to-have feature than a must-have at this stage. The idea is to place your device, such as the Galaxy S6, on a compatible wireless charging mat. While it may be convenient, wireless charging likely won't take off until the technology is built into everything from cars to furniture.
Popularized by the iPhone's Touch ID sensor, fingerprint security on smartphones makes it easier to unlock your device. You can also use Touch ID to buy items in the App Store and real-world goods via Apple Pay. The Galaxy S6 offers an improved fingerprint scanner over the Galaxy S5, which will support the upcoming Samsung Pay service.
Go Through Carrier or Unlocked Route?
One of the biggest trends in smartphones is the rise of affordable, unlocked phones. Instead of going through your carrier to get a device, you can buy a well-equipped handset for hundreds less than a typical flagship phone like the iPhone 6 or Galaxy S6 and still get a great experience. The Alcatel Onetouch Idol 3 is a great example, offering a big and bright full-HD, 5.5-inch display in a lightweight design, with a robust camera, all for $249. That's compared to $649 for the full price of the iPhone 6 and $684 for the Galaxy S6.
This route isn't for everyone, though. You'll still need to sign up for service through a wireless provider and get a SIM Card for your unlocked phone, once you've determined which networks that unlocked phone supports. Most unlocked phones not purchased through the carriers themselves tend to work with AT&T and T-Mobile.
To stay competitive and answer the unlocked threat, wireless carriers are becoming more flexible with their plans, offering off-contract options and new ways to upgrade your device more often.
The 'Big Four'
The vast majority of smartphone shoppers choose one of the "Big Four" carriers: AT&T, Sprint, Verizon and T-Mobile.
Of the three major contract carriers (AT&T, Verizon and Sprint), Verizon offers the broadest 4G LTE network, with a significant performance boost called XLTE. This upgrade doubled the LTE bandwidth and delivered faster peak speeds in various cities. AT&T is typically behind Verizon in LTE speed but claims that it offers the strongest LTE signal.
T-Mobile's performance has drastically improved over the past couple of years, even though some coverage holes remain. It generally offers more affordable pricing than Verizon and AT&T. Sprint has been a distant last in terms of 4G footprint. Its fairly new Spark LTE service offers faster speeds in some markets, but we've seen inconsistent results in various locations. However, Sprint is being the most aggressive when it comes to deals, promising to cut AT&T and Verizon Wireless subscribers' bills in half.
Three out of the Big Four wireless carriers — AT&T, Sprint and Verizon — sell smartphones with two-year contracts. If you leave within that two-year agreement, you'll be subject to an early termination fee (ETF). For example, Verizon charges $350, minus $10 for each full month of your contract term you complete.
The benefit of a so-called subsidized plan is that you pay less up front for the hardware. However, you can decide to pay full price for the handset if you do not want to go the contract route. T-Mobile is the only major U.S. carrier that has ditched contracts altogether, letting you pay off the phone in monthly installments. But more and more shoppers are choosing to go the no-contract route on all of the major carriers, because you can pay the hardware off in monthly installments.
Verizon and AT&T both offer shared data plans (with unlimited text and voice), which allow you to use a pool of data for smartphones and other connected devices like tablets. If you opted for one of these two carriers' monthly installment plans when buying an iPhone 6, you'd pay significantly more on Verizon.
Sprint offers your choice of shared data plans or unlimited plans, which start at just $50 for talk, text and unlimited data for the iPhone for Life Plan. T-Mobile's Simple Choice plan costs more, but the carrier's Data Stash perk lets you roll over data that you don't use in one month to the next month. In response, AT&T has introduced its own data rollover feature. However, the 10GB T-Mobile plan lets you roll over data throughout a given year, whereas AT&T's allotment expires after a single billing period.
The fastest-growing segment of the phone market is off-contract, which means that you don't have to sign a two-year agreement when you purchase your device. Although you'll pay full price for the phone, you'll save money in the long run because you'll pay less per month for service. In fact, some off-contract carriers charge only half as much as their bigger brethren.
Major players in this category (other than T-Mobile) include MetroPCS, Virgin Mobile, Boost Mobile and Cricket.
T-Mobile and MetroPCS share the same network, which gives users of the latter carrier more coverage. MetroPCS currently charges a very reasonable $50 for unlimited 4G LTE, talk and text, 4GB of which is high-speed LTE.
Other off-contract providers charge even less. Virgin Mobile, for example, starts at just $35 per month for 300 minutes and 2.5GB of high-speed data. However, stepping up to unlimited minutes costs $55 per month, and only 3GB of high-speed data is included. The carrier rides on Sprint's nationwide network, as does Boost Mobile.
Cricket, which uses AT&T's network, charges $35 monthly for 2.5GB of LTE data and unlimited voice and text, and costs $50 for 5GB. (That's with the auto-pay option.) Power users will like the $55 Pro Plan, which includes 10GB.
The disadvantages of going with a smaller prepaid carrier include a more limited selection of smartphones (in most cases) and paying full price for the handset. As of this update, Boost, Cricket and MetroPCS all offered the Galaxy S6 for $649, but Virgin Mobile didn't yet carry the device.