Though LG's smartphones sell pretty well, they aren't nearly as popular as Samsung's. But is an underdog like LG more likely to push the smartphone envelope? Let's plop down LG's latest flagship, the G3, next to the Samsung Galaxy S5 to compare their features and specs.

Size

Right out of the gate, we sure aren't seeing any huge differences. Both the G3 and Galaxy S5 are pretty big phones, with the G3 measuring about 3 percent longer, 3 percent wider and 10 percent thicker.

Weight

Another minor difference here, with the G3 tipping the scales at just 3 percent heavier than the GS5.

Build

How does a smartphone-maker cut down on its costs, without necessarily looking like it's cutting down on its costs? Why, by using a plastic exterior that looks like it might be something more premium. Don't be fooled though: both of these phones are indeed made of plastic.

Colors

Each phone ships in several different color options. We didn't include them here, but Japanese Galaxy S5 shoppers also get Sweet Pink and Champagne Pink color options.

Display (size)

If you weren't already convinced that the lines between flagship smartphones and flagship "phablets" were getting blurred, look no further than the G3. We're comparing it to the Galaxy S5, but its screen size is actually closer to that of Samsung's oversized wonder, the Galaxy Note 3.

If you haven't already noticed, the G3's front face makes better use of its space than the GS5 does. Both phones have very narrow side bezels, but the G3 has less bezel above and below its screen.

Another thing to keep in mind about display size is that the G3 sacrifices a little bit of its screen for virtual buttons. The Galaxy S5's navigation keys sit below its screen, freeing up its entire display for your apps and content.

Display (resolution)

This is the G3's killer feature. For all of LG's bloated PR talk about "Simple is the New Smart" (as if most tech companies weren't already focused on consumer simplicity), the real draw here is the G3's 2K display.

You could argue that 538 pixels per inch is overkill, as the GS5's 1080p display is already past the threshold where most eyes will notice individual pixels. But, either way, the G3 is breaking new ground in smartphone display resolution. The biggest question is how its battery life will hold up, driving those 3.6 million pixels.

Water resistance

Speaking of killer features, the GS5's is its IP67 water resistance. It can sit in 1 meter (3.3 ft) of water for 30 minutes, and come out as good as new. Just be sure to tightly seal its battery and charging covers beforehand, or you might find yourself shopping for a new phone.

Fingerprint scanner

It might not be quite as user-friendly as the iPhone's Touch ID, but the GS5's swipe-based fingerprint sensor can still be a handy security feature. Once you teach it your fingerprint, you can use it to unlock your otherwise passcode-protected phone. It also plays nicely with a few third-party apps, including PayPal and the LastPass password manager.

Heart rate monitor

If you want to check your pulse on the go, then the GS5 has a dedicated heart monitor on its backside. It's a nice bonus, but you can achieve a similar end on the G3 (along with most other smartphones) with third-party apps that use the camera and flash to measure your pulse.

Processor

Nothing to base your decision on here, as both phones run Qualcomm's fast Snapdragon 801 processor. Though some international markets will get an octa-core Samsung Exynos CPU in the Galaxy S5.

RAM

The amount of RAM in the G3 varies depending on which storage tier you opt for. 16 GB of storage gets 2 GB of RAM, 32 GB of storage gets 3 GB of RAM. That kind of split is common with laptops, but I can't say I've seen that before in a smartphone.

Storage

Both phones offer 16 GB or 32 GB of storage, and also support microSD cards.

Battery

The G3's battery has 7 percent more capacity than the GS5's. But, then again, it's also powering a display with 78 percent more pixels. So battery life is going to be the biggest thing to keep an eye on before throwing down for the G3 (stay tuned).

Removable battery

If you end up plowing through your battery's juice and want to swap for a new one on the go, then either phone will fit the bill.

Ultra Power Saving Mode

The Galaxy S5 has an innovative new feature that can perhaps save you from needing a backup battery. If your GS5's battery life gets too low, just switch on Ultra Power Saving Mode, and watch as your screen shifts to black & white and severely limits available apps (you'll have basics like email, messaging, phone and web). In Ultra Power Saving Mode, Samsung estimates that 10 percent of juice will last you an extra 24 hours. It might be the most innovative software feature Samsung has ever come up with.

Cameras

The Galaxy S5 takes great shots (well, for a smartphone), but its camera app is also notoriously slow to load. We haven't yet put the G3's camera through the paces, but LG is promising lightning-fast shooting and a laser-based focusing system that determines the distance between camera and subject.

Infrared

Both phones let you use them as remote controls for your TV or cable/satellite box, courtesy of their built-in infrared.

Software platform

Both phones ship with Android 4.4 KitKat, along with their own respective custom skins on top. LG revamped its smartphone UI this time around, with – go figure – a flat design.

Release

Few carriers have announced specific release info for the G3, but it's already on sale in LG's native South Korea. The GS5 launched in early April.

Starting price (off-contract)

Pricing for the G3 could vary from carrier to carrier, and we don't know much on that front just yet. If I had to bet, though, I'd say something close to the GS5's US$650 off-contract price would be a safe choice.

We're just scratching the surface with this quick specs-based rundown of the G3. Stay tuned for more, as it starts to roll out across the globe. And for more on the GS5, you can hit up our full review of Samsung's flagship.