The company announced the news via the Sony Mobile Blog and also noted that the update is now rolling out, though the usual timing and availability of the update for the Xperia Z1 and Xperia Z Ultra will vary by market and mobile carrier.
Sony has also revealed the changelog for the Android 4.3 Jelly Bean update for Xperia Z1 and Xperia Z Ultra. Some of the changes included are UI optimisation bringing Project Butter performance; redesigned native apps (messaging, MyXperia, Smart Connect, Small apps, TrackID, Sony Select among others) and Sony's media apps (WALKMAN, Album and Movies) are now integrated with a more intuitive UI, offering access to both local and cloud content.
In addition, Sony has also announced the addition of custom interface experience called 'Xperia Themes', with downloadable UI packs from Sony Select. Sony also confirmed the inclusion of Sony's Smart Social Camera to Xperia Z Ultra phablet, which was initially introduced with the Xperia Z1. The Smart Social Camera app allows users to download and access the 'Xperia camera apps' within the viewfinder.
Sony has also revealed that the Android 4.3 Jelly Bean update for more Xperia smartphones is around the corner and the company will announce it soon.
In November, Sony had confirmed that the Android 4.3 Jelly Bean update will be rolled out to devices such as Sony Xperia SP, Sony Xperia Z, Sony Xperia ZL, Sony Xperia ZR and Sony Xperia Tablet Z in December.
Additionally, Sony had revealed that the Android 4.4 KitKat rollout plan for Xperia devices would update include Sony Xperia Z1, Sony Xperia ZL, Sony Xperia Tablet Z, Sony Xperia Z Ultra and Sony Xperia Z. However, Sony did not mention a specific timeline for the upcoming Android 4.4 software update.