Sony recently launched its flagship smartphone for 2015 — the Xperia Z4 — which is the successor of the Xperia Z3.

We take a look at how the Xperia Z4 compares against the company's old warhorse Xperia Z3.

Processor

The Xperia Z4 houses an octa-core Snapdragon 810 processor, which is clocked at 2 GHz. This improves on the quad-core Snapdragon 801 processor clocked at 2.5 GHz found in the Xperia Z3.

The graphics also see an improvement with the Xperia Z4 packing in Adreno 430 vis-à-vis Adreno 330 on the Xperia Z3.

Display

The Xperia Z4's screen size does not get a boost when compared with its predecessor. Both the Xperia Z4 and Xperia Z3 sport the same 5.2-inch full HD screen with a resolution of 1920 by 1080 pixels. The pixel density for both is 424 ppi.

Like the Xperia Z3, the Xperia Z4 has a triluminos display and shatter-proof glass. Both Sony smartphones are IP68 certified and are dust and water resistant (for over 1 meter or 3.28 feet for 30 minutes).

Dimensions

The Xperia Z4 measures 5.75 x 2.83 x 0.27 inches compared with the Z3's 5.75 x 2.83 x 0.29 inches dimensions, making the 2015 model fractionally thinner. The Xperia Z4 (5.08 oz) is also .28 oz lighter than sibling Xperia Z3 (5.36 oz).

Design-wise, Sony has made some noticeable changes to the Xperia Z4. It is not only slimmer and lighter than its predecessor, but the smartphone's edges have a shiny metal frame.

Memory

The Xperia Z4 comes in 32 GB and 64 GB on-board storage options, which replace the 16 GB and 32 GB options on the Xperia Z3.

The Xperia Z4 also packs in the expandable memory option, which is same as the Xperia Z3 — 128 GB. Both Sony smartphones offer the same memory capacity of 3 GB of RAM.

Camera

Like the previous iterations, the Xperia Z4 touts a 20.7 megapixel rear-facing shooter with autofocus, LED Flash, geo-tagging, face detection, touch focus, panorama, HDR and a 1/2.3-inch Exmor RS sensor. Wondering what's new? The "cooking mode" for those who like to share pictures of their cooking and the "premium Random Auto" mode, which provides backlight in a dark setting to recognize the same and automatically adjusts the optimal settings for the perfect picture.

The front-facing camera on the Xperia Z3 was 2.2 megapixels, but with selfies being all the rage, Sony is moving with the times and the Xperia Z4 sports a 5.1 megapixel camera.

Operating System

The Xperia Z4 will come with Android 5.0 Lollipop out of the box, whereas the Xperia Z3 is already receiving the Android Lollipop update.

Battery

The Xperia Z3 has a non-removable 31000 mAh battery that offers up to 16 hours of talk time support (on 3G). The Xperia Z4 houses a 2,930 mAh battery, which is a downgrade from the predecessor. The smaller size could possibly be owing to the new smartphone being thinner. Sony, however, claims that the Xperia Z4's battery will offer up to 17 hours of talk time on 3G.

Colors & Availability

The Xperia Z4 will be available in four hues: white, copper, black and aqua green. Sony has done away with the purple option. The Xperia Z3 comes in five colors: black, copper, white, silver green, and purple.

The Xperia Z4 is slated to release in Japan in summer this year, and the pricing is unknown. The smartphone is anticipated to make its way to other parts of the world later. It is likely to be priced around the same mark as the Xperia Z3, which cost $680 for the unlocked version at launch.

The latest Xperia Z4 from Sony is not a major improvement on its predecessors and does not bring any revolutionary features users' way. Whether minor improvements will be enough to keep Sony's flagship smartphone relevant in the competitive consumer space remains to be seen.