How to root the Samsung Galaxy S3 for custom ROMs and root apps

Rooting an Android phone opens up all manner of apps and hacks to expand your phone’s capabilities and it’s crazy that more manufacturers don’t support it by providing brick-proof recovery options and straightforward rooting procedures.

Things are improving though. The last smartphone I rooted was the HTC One X and that was incredibly easy thanks to HTC supplying the software and steps.

Doing the Galaxy S3 was even more painless because of the hard work of XDA Developers forumite Mark Skippen who has created a toolkit which removes any hint of hassle. Having spent hours mucking about with other phones this was so easy it almost doesn’t feel right.

Want to root your own Samsung Galaxy S3? Just follow these steps.

Before you start

You'll need a Windows PC, your phone's USB cable and a Galaxy S3.

Check you have the right phone

This guide is for the international GSM model with an Exynos CPU. There are multiple variants across the world, particularly in the US, some of which have a Snapdragon processor. This guide is not for those models.

On your handset go to Settings > About and check that the model number is GT-I9300. Also make a note of the last four digits of the build number and the Android version.

Uninstall Samsung Kies

On your computer go into Programs and Features (or Add Remove Programs) and uninstall Samsung Kies if it is present. Android USB Drivers may also be listed here but you can leave these as we’ll need them.

Enable USB debugging

Go to Settings > Developer Options and switch on USB debugging.

Backup important files

This rooting process does not wipe the handset but if something goes wrong you could lose data, so keep a copy of anything important.

A friendly warning

The Toolbox is easy to use and relatively safe but rooting always carries a risk. It is possible your handset could be permanently bricked, or at least temporarily disabled. So keep that in mind.

One thing that every S3 owner should be aware of is that rooting invalidates your warranty. It’s silly that a software modification should prevent a hardware repair but that’s Samsung’s policy. While you can reset the phone back to its original state to remove the files placed there by the rooting process Samsung introduced a new ‘feature’ in the S2 which records whether the handset has been modified, displaying a warning triangle in download mode.

This can be removed with the Triangle Away app but that carries a much greater risk of bricking and does not work on every S3 so rooting your phone may mean you will be unable to request a warranty repair at a later date.

How to root the S3

1. Download and install the Samsung Galaxy S3 Toolkit

2. Run the Toolkit. In the first step you’ll need to select a matching phone model and build. 

The build does not need to match exactly, you can choose the next one up or down so long as you are running the same version of Android. For example, I had Android 4.0.4 with build BLG8, so I went option 4 (BLG9).









3. Connect the S3 via USB in MTP (media) mode.

4. This is the main Toolkit menu. If you already have the USB drivers the serial number will be shown at the top under ‘ADB MODE’. If not, disconnect your handset and select option 1, following the steps to install the drivers.

[Driver troubleshooting tips: uninstall Samsung Kies, reboot your computer after installation, ensure USB debugging is enabled]









5. Once the phone is correctly detected, select option 2.

6. In the next menu choose option 3. This will give you the complete package: rooted boot image, Superuser, BusyBox and ClockworkMod Recovery.









7. Wait until it prompts you to continue then type yes to proceed.

8. Your handset will reboot into Download Mode. Don’t mess with it. Another window will pop open on your computer, this is Odin. Say hello. Keep Odin and the Toolkit side by side so you can follow the instructions.

9. As it instructs, click the PDA button on Odin and locate the .tar file for your handset. Ensure that only Auto Reboot and F.Reset Time are ticked then click Start.





10. Let Odin do its thing. The Toolkit will tell you to exit once ‘RESET’ or ‘PASS’ appear in the top left corner, but the exit button stays greyed out. I exited the old fashioned way by clicking the X close button.






11. The Toolkit will detect that Odin has closed and continue by itself. Just wait while it installs Busybox and CWM and runs through the checks. Your phone will reset and the Toolkit will indicate when it’s finished.









12. You should now have root.








If you reboot your handset into Recovery Mode by switching it off then back on while holding power, volume down and home you’ll get access to CWM Recovery, through which you can save a full backup of the phone (recommended) and install ROMs and other goodies.

If you’re wondering what to do with your newly rooted Galaxy S3 we’d recommend trying the following: ROM Toolbox, Titanium Backup, Call Master, Tasker, Juice Defender, Avast! Mobile Security, Market Enabler and DroidVPN. Lots more can be found on Google Play. 


  • unhappy

    by Imad Darwish at 13:42 on 31 Aug 2012 Report abuse

    I've done all the steps 1000% correctly as you says, and once the phone restarted to downloading mode, it stucks on downloading... and never got any further action :(

    and on Odin3 when i choosed the PDA C:\Samsung Galaxy S3 ToolKit\root\boot-insecure-xxblfb-cwmtouch-gsm.tar and then i Pressed "Start" it gave me this message All threads completed. (succeed 0 / failed 0)

    any clue ???

    Thanks in advance

  • neutral

    by Deb at 6:05 on 1 Sep 2012 Report abuse

    When I get to Odin, my phone doesn't get detected :( Reinstalled drivers and still didn't work.

  • Matt Powell - EditorEditor - Matt Powell

    by Matt Powell at 12:02 on 1 Sep 2012 Report abuse

    Is your phone detected by the Toolkit? You should have a serial number displayed in the main menu (as per the image on step 4).

    Imad - not sure what's going on with yours. Maybe try reinstalling the drivers? It's definitely not been rooted before?

  • happy

    by Shaz at 4:21 on 2 Sep 2012 Report abuse

    Thank you very much for this page. Worked a dream, quick and easy... Sorry for the guys above that it didn't work for but my s3 is nicely rooted now, off to explore the wonders of this phone.

    Thanks again

  • happy

    by josephwills at 11:55 on 7 Sep 2012 Report abuse

    I tried it and it really worked.If someone getting a problem he /she should do it again , hopefully it works.

  • neutral

    by RichardBohannon at 0:51 on 9 Sep 2012 Report abuse

    I've rooted my Slll but now the cyanogenmod is not loading and its stuck I can't navigate to the download page to stop it

  • neutral

    by Aj at 6:39 on 10 Sep 2012 Report abuse

    My s3 build is :XXLH1 which one form me ?

  • neutral

    by maira hedge at 7:27 on 11 Sep 2012 Report abuse

    i think hard reset can be a part of this, i am having a hard reset process with me right now if am not wrong. i guess the steps for hard reset remain same for both GS2 AND GS3, if yes, here is the full procedure have a look I got a strong feeling while I was reading your Blog and thought of contributing a little to help people who are facing issues on their GS2. thanx

  • happy

    by Pedro at 21:32 on 11 Sep 2012 Report abuse

    Just to say thanks for the tutorial, worked a treat. Only thing that didn't work for me was the booting into recovery / clockworkmod....had to use vol up instead of down. Thanks again!

  • happy

    by Arnt at 2:22 on 22 Sep 2012 Report abuse

    Thank you for this easy to understand tutorial, Matt! :-)

  • neutral

    by Tuyre at 20:26 on 22 Sep 2012 Report abuse

    Followed the instructions and it worked 1st time. However after installing Samsung's Kies, it tells me there's a firmware update available, but I also have seen warning that updating a rooted phone may brick my phone. Can you comment on what steps I should take to upgrade to the latest firmware?

  • neutral

    by Tuyre at 2:17 on 23 Sep 2012 Report abuse

    An update from me (see previous post). I simply updated via Samsing Kies, and re-ran the rooting software afterwards. All was fine.

  • neutral

    by Saber at 11:57 on 26 Sep 2012 Report abuse

    I got 4.0.4 IMM76D BLH9... What option should i use?

  • neutral

    by woody at 19:16 on 4 Oct 2012 Report abuse

    I have flashed the DLIB jelly bean update to my s 3 can get still root my phone now with this rom on it

  • happy

    by Thet Tin Oo at 11:15 on 15 Nov 2012 Report abuse

    your genius ! I got 100 % done.

    Thanks a lot...

  • happy

    by Matt-Boi at 8:12 on 8 Dec 2012 Report abuse

    Cheers guys excellent read worked first time, rooted backed up and updated f-rom thanks again.

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