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Android 12 stock official update is rolling out, BUK8


Extreme Android User
Aug 17, 2010
Cotswolds, England
Samsung have begun rolling out the first official stock update of Android 12, One UI 4, for the S21 series of devices...

The Galaxy S21 Global, Exynos, devices that will receive this update are...

  • S21 5G model SM-G991B
  • S21+ 5G model SM-G996B
  • S21 Ultra 5G model SM-G998B
This latest release replaces the previous G99*BXXU3ZUK1 / G99*BXXS3AUJ7 builds.

It is a FOTA, (Firmware Over The Air), update and you can check... Settings > Software update... to see if it is available for you. Alternatively, you can connect to the Samsung PC suite, Smart Switch and check via that.

Changelog (for those coming from Beta)


The update = G99*BXXU3BUK8

Download = 290.45MB (for Beta testers) 2670.68MB (for non Beta testers)

Build date = 05 November 2021

Release date = 15 November 2021

Camera version =

One UI version = 4.0

Android Security patch = 01 November 2021

This is the 20th stable update in 294 days. Average = 1 update every 15 days.

Wipe the phone's cache partition and use the Galaxy App Booster after updating.

(N.B. This post will be updated as more information becomes available)
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Samsung have had a huge release of the latest Android 12, One UI 4, stable release, BUK8, with 80+ CSC codes updated for countries and carriers, worldwide in the last few hours.

This includes those in the U.K. on the carrier branded S21 devices for O2 on CSC code = O2U.

No news, so far, on the last remaining U.K. carrier branded S21's for Three network on CSC code = H3G.
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Only 10 days after beginning, Samsung has virtually completed the roll-out of Android 12, One UI 4, to over 100+ of their global branded and unbranded Exynos devices for Europe, Asia, Africa and the Nordic and Baltic regions.

It is now the turn of South America to receive Android 12 beginning with its release to the Chilean non-carrier branded devices on CSC code, CHO.

No news I'm afraid on when Australia and New Zealand will be updated yet but it shouldn't be too long.
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