The line-up in 2013 brought an entirely different design of phones, first seen on the Xperia Z smartphone, and called 'OmniBalance' (roughly translated as 'balance everywhere') by Sony.
In 2014 Sony stated to be focusing more on the high-end phone market and reducing the number of low and mid-end products.
The first model launched in 2015 was the Xperia Z3+, featuring updated internals in a body similar to the Xperia Z3.

In 2016, Sony introduced the Xperia X series at MWC 2016 to replace the Z series.
The last device to launch under the Xperia X series was the Xperia XZ3, a flagship device released in late-2018 featuring an OLED display, a first for Sony smartphones, then it got replaced by the number series introduced on the Xperia 1 in 2019.
The line-up in 2013 brought an entirely different design of phones, first seen on the Xperia Z smartphone, and called 'OmniBalance' (roughly translated as 'balance everywhere') by Sony. In 2014 Sony stated to be focusing more on the high-end phone market and reducing the number of low and mid-end products. The first model launched in 2015 was the Xperia Z3+, featuring updated internals in a body similar to the Xperia Z3.
In 2016, Sony introduced the Xperia X series at MWC 2016 to replace the Z series. The last device to launch under the Xperia X series was the Xperia XZ3, a flagship device released in late-2018 featuring an OLED display, a first for Sony smartphones, then it got replaced by the number series introduced on the Xperia 1 in 2019.
Sony Mobile