Just last month, Sony had officially announced the Xperia Z4 and unveiled details of the smartphone on its Japanese website. The Xperia Z4 will be initially available only in Japan and should hit the stores there this summer, though Sony did not provide any information regarding its global release or price. A new report now claims that Sony will launch the Xperia Z4 with the Xperia Z3 moniker outside Japan, which is in line with earlier reports of the Xperia Z4 not being the company's 2015 flagship for global markets, with the real flagship being reportedly slated for launch by the end of May.

At a press conference held in Japan on April 20, Sony had officially unveiled the Xperia Z4 and made details of the flagship smartphone public at on its Japanese website. Since the Xperia Z4 was only announced in Japan, it sparked rumors that the smartphone was a Japan-only device. This rumor now seems to be more or less confirmed as a Russian site Mobiltelefon has reputedly spotted a Sony SCR30 Style Cover Window accessory description mentioning support for "Xperia Z4/Z3 ".

Sony's Xperia Z4 is a minor upgrade over the Xperia Z3, with both devices having matching specifications, apart from the front-facing camera and processor. Since the Xperia Z4 is more or less similar to its predecessor, the new smartphone is not really a flagship model, which suggests that it could be launched globally with the name Xperia Z3 .

However, the international variant Xperia Z3 will reportedly arrive with the same configurations as those of the Xperia Z4. According to the specifications of the Xperia Z4 listed on Sony's launch page, the device features the same 5.2-inch full-HD display as its predecessor with a 1,920x1,080-pixel resolution, but has a thinner 6.9mm form. The Xperia Z4 is powered by Qualcomm's 64-bit octacore Snapdragon 810 processor paired with 3GB of RAM, and has the same 20.7-megapixels rear-facing camera, as well as a 5-megapixel front-facing camera with wide-angle lens.

The Xperia Z4 comes with 32GB of internal storage, which can be expanded up to 128GB via a microSD slot. Sony's new flagship device packs a 2,930mAh battery and runs Android 5.0 Lollipop out of the box. The Xperia Z4 also comes with an IP6X dustproof rating, and is certified IPX5 and IPX8, making it splash-resistant and indicating its ability to survive even after being submerged in water for a long period. Sony is expected to launch the Xperia Z3 in select countries this month.