Update Galaxy S3 with Official Jellybean 4.2.1 XXUFMB3 Firmware – Guide

Galaxy S3 Hyderabad LogoIt’s a Step Up for the users of Samsung Galaxy S3 GT I9300 smartphone as an all new Official build of Jellybean 4.2.1 firmware has arrived and in the due course of this article we will be checking out the same on how to apply this. Please note that this is the Official firmware which got leaked from Samsung and is not a custom ROM firmware. Applying this update won’t hamper the process of firmware update. There were couple of firmwares which was having the Jellybean build but this built is one of the most stable builds along with which it’s also having many new features which we have mentioned below;

Before we proceed to the detailed tutorial on how to apply this firmware update, let’s check out on what are the detailed change log of this new build of Jellybean 4.2.1 firmware which is dubbed as XXUFMB3.

Change log of Jellybean 4.2.1 Firmware:

  • Based on JOP40D Jellybean 4.2.1 Firmware,
  • Bugs are fixed in Ripple Effect on Lock Screen,
  • New Lock Screen and Widget Support as its Jellybean 4.2.1,
  • Daydream (Settings>Display)
  • New Additions in Notification Center
  • Notifications are more actionable
  • Voice Command (Allows you to control various parts of the phone using voice commands)

Quick Pre Requisites:

  • All the data in your Samsung Galaxy S3 i9300 smartphone should be backed up manually and not with KIES or ROM Manager as it may brick the device completely. With the help of below mentioned steps, you can easily create a backup.

SMS – Use “SMS Backup & Restore app”,
Contacts – Sync with the Gmail application,
Call Log - Call Log and Restore
Images, Songs, Videos, Files – Copy to internal / External SD Card,
APN and MMS Settings – Note down from the path “Applications > Settings > Wireless and Network > Mobile Networks > Access Point Names

  • From the path “Settings > Applications > Development > USB debugging”, enable the USB Debugging and also make sure that your device is left with the minimum of 40% or the device will get turned off in the middle of customizing process. Ensure that your device is not rooted.

Disclaimer: Though we don’t like to give any disclaimers, the only thing we would like to tell you is that please follow all the instructions mentioned in this article or else there is a risk of bricking your device for which we should not be held responsible.

Let’s proceed to the next step where we have summed up a detailed guide on how to apply this firmware update.

Procedure to Update Galaxy S3 GT I9300 with XXUFMB3 Jellybean 4.2.1:

  • Now, turn Off your phone so that it can be entered in the Download Mode. Download mode in Galaxy S3 GT I9300 can be entered by pressing Volume down Key, Center button, and holding both simultaneously press the Power Button after which you will get to see a green robot indicating that the device has entered in the download mode.
  • Connect your Galaxy S3 to the computer with the help of original USB cable and then you will see that the ID : COM section will turn Yellow indicating that all the drivers have been installed successfully.
  • Click on “PDA” option to select “” and click on “Start” to start the process of firmware update. Once the firmware is updated successfully, you will see that the firmware application process will be commenced.
  • Once the firmware is updated successfully, the device will be rebooted. Till you see the country selection option, don’t pull out the USB cable.
  • Once you see the home screen, disconnect the device and head over to the path “Settings > About Phone” where you will be able to see the firmware version as Jellybean 4.1.2 firmware XXUFMB3 Jellybean 4.2.1.

Tip: Just in a rare case if the device doesn’t boot up or gets into the continuous Boot loop mode, you need to reinsert the battery and boot the device normally. Or else you need to re-apply the update by following the steps above.

So, there you go, you have now successfully applied the update of Jellybean 4.2.1 firmware. Do let us know if you come across with any issues as we will try our level best to sort out the same.


  1. yeah this 4.2.1 updates cool..just it middle east stock..has to factory reset then its ok..but how to disable the jews calendar???? thanx mr.pradeep nela..email me if there is 4.2.2 update..or any file that s4 has can use for s3 without rooted

  2. SimonJPA Baillargeon

    Pretty much all the links are working, but the SMS Backup & Restore app.

    Just copy and paste the name on Google to find the APK file.

  3. SimonJPA Baillargeon

    I had to do this update of firmware, because I had updated the version of my Samsung from 4.1.1 to 4.1.2.

    4.1.2 it’s junk! It’s worthless, just bugs and bugs.

    Now with this installed my Galaxy S3 has never been so FAST!


  4. Alaric Fernandes

    Fonts cant be changed. Error: Invalid font. They worked on all other roms. tried downloading and installing again.. no go. tried different fonts.. no go.. any suggestions..?

  5. This link do not work have treid is since 05/04/2013 about 10 times Hotfile reply file can not be found Pls.help

  6. Hi!
    Thank you for this update!
    Only 2 problems from my side..
    1 smart stay icon stays on even when off!
    2 The signal bar has no bars inside, so it looks like I dont have signal when I do.

    • Alaric Fernandes

      Smart stay is stuck on the screen, it lights up for a second when it looks for ur eyes. Its not a problem, thats how it is. Clear Dalvik Cache for the 2nd issue. If that doesnt work, factory reset.

  7. Hello, spanish language suported? thanks..

  8. i did the clear and wipe data but getting the same black shadow on top….. plz help

  9. The Upper side of the screen becoming black … please provide solution immediately….

  10. one more thing smart stay eye always available on the top corner whether we activated it or not.

  11. call by scrolling left to right not working.And another bug is screen clarity at upparside becomes dark. please provide fix for these things. It will help alot.

  12. First of all I think there’s a mistake in the article: “All the data in your Samsung Galaxy S3 i9305 smartphone ” – shouldn’t it be I9300?
    Now the question – will this set the Device Status to Modified (increase custom binary count)?

  13. si es oficial de samsung quiera saber para no joder mi celu

  14. quiera saber si es un firmware oficial este q esta aca para descargar no quiero joder mi samsung galaxy s 3

  15. Where have they hidden photosphere if its included?

  16. hey after update my polaris office n photo editor does not work ne solution fo tht n can i xpect for better 4.2 version soon or how long will i hv to wait???

  17. do we hv to mark factory reset option in odin while updating?

  18. are the message and developer options still persistent. And is photosphere included in this version?

  19. Messages only worked after factory reset .now very good . Happy

  20. This firmware is buggy. Touch becomes slow. Sometimes not working while we have to call to another by scrolling left to right. At that time we have to close phone calling menu then reopen it and then working. Its bug. And another bug is screen clearity at upparside becomes dark.

  21. any fix on the sms issue? Installed twice and cleared the cache each time with no luck

  22. guys is it safe to try this update? please advice.. im using s3 international version and im in malaysia.. im now on 4.1.2 i9300XXEMA2.. what will happen if i update to this firmware?

  23. my phone is already rooted , can i proceed with the update or i have to unroot the phone first

  24. After the upgrade which seems to have worked fine, i can not find the usb debugging option or indeed the entire developer menu. could you advise where it is after update please.


  25. Cleared cache from recovery mode but it’s still not working… any other ideas?

    • just re apply the update

      • Did just the same. Tried to clear the cache – successful. re-applied the firmware – successful, still messaging does not work. Also, DDELLC is not getting patched.. trying it for the second time now

  26. No está disponible con el idioma Español ??

  27. this tripped my custom binary dl (yes 1 count)
    message crash, time to downgrade

  28. i m from india,shall i update this firmware n what abt the rooting package for this firmware. thank u

    • yes you can apply teh update, we will be coming up with the rooting process very soon

  29. This can’t be the official one its terrible, phone keeps locking up.
    I need to go bave to a previous as its unusable.

  30. cant find developer options after update..??

  31. after jb update of my gt19300 i cant hear wat someone says wen they call me or can they please give me a sol

  32. I can not open messages either. And it does NOT help to clear the cache!
    But worst of all, I have tried to roll-back to XXELLA firmware, but the phone will not start up. It just keep showing the Samsung logo.

    How can I solve this problem?

    • just clear the cache and wipe the data to re apply the update

      • I have probably found the cause to why many people (including myself) cannot open messages after applying this firmware.
        The XXUFMB3 firmware does only have English language and some I believe is Arabic. Therefore, I believe that maybe that can be the reason why messages does not work since my phone configured to Danish.
        After I went in recovery mode and “Wipe Data/Factory Reset”, I could install XXEMB5 without any problems.

        This is the first official firmware I have seen that has not all languages included.
        Do you have an ETA when there will be an official 4.2.1 or 4.2.2 firmware with all languages included?

  33. I clear the cache from the recovery mode and doesn’t work message app.Why?
    Thanks !

    • we are looking into the same, there should be no issues after clean installation…

      • Pradeep , SMS appp is nt working for me , I have tried clear all the data from Rec. mode , still no luck. Now Can I downgrade to 4.1.2 official version ??
        How do I do that ?

  34. Hi! Why isn’t recognize by Kies?

  35. Is the SMS apps working now?

  36. Dear Pradeep,
    Does this firmware apply to both S3 models viz GT-I9300 and GT-I9305 ???

  37. The message app doesn’t work.

    • clear the cache from recovery mode and then check, it works for us

      • hi neel,

        i am nithin, i am a huge fan of android advices, i am using galaxy note 2, my previous smartphone was galaxy s2 and did all my updates frm ur website, all the official firmwares like ics, jellybean etc.
        now i am using note2 and i cannot find any official updates released by this website, r u not dealing with note 2 ???

      • clear the cache from recovery mode does not fix the SMS for me.

        DO I need to do a factory reset as well?

  38. messages will not open after installing update

  39. It’s very good. I can’t send messages and i have 3 useless apk’s inserted in the software.

  40. Must the phone be rooted to apply this updated?