Backup/Restore EFS data of Samsung Android Device, to Fix IMEI and SIM not detecting issues

There are lot of rooting guides and flashing guides over there in the market and often most of android users use them in their android devices. Accidently sometime cause of wrong guidance or cause of an external error or we face troubles of loosing data and the main corruption of EFS partition. Yes EFS partition that’s the considering thing here. Let I first introduce you about this EFS.

What the hell is this EFS ?

EFS partition is actually a internal place in our android device such as android phone which contains some important and some basic info related to our device identity like Wi-Fi address, Bluetooth MAC address and the very main IMEI address (nv_data.bin).

Now if this EFS partition accidently corrupted then your phone’s IMEI no. will erased and you can not make voice call further. This kind of damage is often not accepted by the service center of your respected handset’s company.

Why should I backup EFS data ?

Few days ago my friend ashwini ranjan , sent me a message – “Kuldeep whenever you get time please call me it is extremely urgent”.

When I called he told me that his phone galaxy s2 is not detecting sim after he flashed a firmware through Odin, I tried a lot but failed to revive phone :(

I know it was problem of EFS data but it is not possible (at least for me) to retrieve IMEI data without having EFS backup. So it is very necessary to make a backup of this EFS partition just now to avoid such type of future troubles.

Now the question is “how to make a backup of EFS partition”. We researched some guides over the web related to this and found some good things.

There are three methods to make a backup of this EFS partition.

1st EFS folder backup using root explorer

Just copy the whole EFS folder via root explorer to your SD card or anywhere in your PC. But according users criteria this method is not be good in EFS restore.

2nd Using kTool by Hellcat


Note: This tool is only compatible with galaxy s2 and galaxy note

kTool-by-hellcat-screen-1  kTool-by-hellcat-screen-2

Using of a backup/Restore tool as “kTool by Hellcat” , this tool will backup your whole EFS partition including read / write permission that makes your phone compatible for this task.

Lets see procedure to make a backup/restore of EFS partition by “HC- kTool”

Required things :

Be aware of :

  • This procedure is valid for only Samsung Galaxy S2 and Note handsets.
  • We are not responsible for any kind of damage and error while applying the process. Do at your own risk.

Video Guide , thanks robifis

Procedure to Backup EFS :

  1. Install the Hellcat kTool from android market in your Galaxy S2.
  2. After installing the kTool just launch it.
  3. At the home screen of kTool you will found some interface tabs, main the backup and restore tabs.
  4. Now first for make a backup of your phone’s EFS partition just tap on the tab “Backup EFS to /sdcard/efs.img”.
  5. After that you will see a progress circle showing with “Dumping EFS…..” written.
  6. This whole process of backup will done in few seconds and you will see a prompt showing “Backup done, verify?” with accepting yes or no.
  7. So tap on “yes” and then “Run Check” to checkout the brief info about the backup.
  8. You will see the info just like in below manner.
  9. After checking tap on “close” and come back to the main menu of kTool.
  10. Now you can also save a copy of this backup file in your PC just by connecting the phone to the PC via USB cable.

Procedure to Restore EFS :

  1. For restore the EFS partition anytime from the backup just tap on the option “Restore EFS from backup (DANGEROUS)” at the main menu of ktool.
  2. After that a prompt will appear written with some warnings and asking you to choose the type of backup file i.e the IMG or TAR to restore from backup.
  3. Here choose anyone as desire, but only then when you hardly need this means your EFS partition is already corrupted.
  4. But at now just cancel it.

Some other functions: By HC-kTool you can also directly reboot to recovery mode and download mode. So be try them at your own.

So as soon as possible make a backup of your EFS partition and avoid the risks occurs during any flash of corrupted ROMs.

Via JayCeooi

3rd Using EFS Pro tool by xda


This is a small windows software it is Compatible with Windows XP, Vista, 7. it can backup efs and restore as well. This tool provides option to save backup on your pc or phone sd card, I recommend both.

Make sure you have Microsoft .NET Framework 4.0 installed on your PC before using EFS pro.


  • Supports Backup and Restore of Partition Image (*.img) and Compressed TAR Archive (*.tar) formats.
  • Automatically detects saved EFS Backups on Device and PC for hassle free restoring.
  • Re-Scan option to refresh Backup list for restoring Backups.
  • Automatically Re-Mounts ‘/efs’ folder with Read/Write permissions during restore for users ‘stuck’ with Read Only permissions.
  • Automatic detection and prompting of Mass Storage Mode.
  • Automatic detection and termination of SAMSUNG Kies application on startup.
  • Supports Multiple Backup handling.
  • Option to Format ‘/efs’ partition before restoring an EFS Backup.
  • Displays Device, ROM and BusyBox information on startup.

Download link for EFS pro and more information is on xda forum

If I missed any other tool then please let me know via comments below , if you found this article helpful then share with your friends


[Credit] – Amit garg , XDA Forum , HellCat , Jayce , robifis , Ashwini for telling me that I should post this guide

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About kày

Kuldeep Singh is founder of androidflip , young blogger from india who loves to write about android and technology. Follow him on twitter @androidflip


  1. hey guys this is a very nice topic, i will backup my efs folder now ! , but my friends phone lost the his IMEI and he didn’t backup his efs folder …. is there anyway to recover his IMEI and the efs folder ?

    best regards and keep up the good work guys ! 😀

  2. hey guys this is a very nice topic, i will backup my efs folder now ! , but my friends phone lost the his IMEI and he didn’t backup his efs folder …. is there anyway to recover his IMEI and the efs folder ?

    best regards and keep up the good work guys ! 😀

  3. great job kuldeep . thanks a lot….

  4. great job kuldeep . thanks a lot….

  5. Frankly admitted, didn’t know how important is this. Now I know, I will back up. Thanks a lot Kuldeep.

  6. hey bro if i ll root my s2 will my imei flash

  7. a very nice topic

  8. Hi Kuldeep. Thank you a lot for this tutorial. I’ve messed up my phone, and I have a copy of /efs folder (using root explorer) made with your first method.
    How can I restore it?

  9. Sir,
    Im using an unlocked sgh-i927 samsung phone. I used my set last night and was working alk welk. When i woke up in the morning only the data connection was working and my cannot get a signal…so neither i can make calls.
    When checked with a cellrepair shop i was told thatt the phn’s imei number has been damaged. Its shows004999900961014 (something like that). Where it starts with 35 on back of my phone.i dont have any backups or other stuff. I bought this phone in canada and now i am using it in india.
    Please help me out with a solution.

    • Kuldeep Singh says:

      This is very normal, my tow friends had this issue before, all you have to do is go to service center and pay for it. without EFS backup you cant fix it at home.

      • hello kuldeep, my galaxy s2 suddenly lost its signal and imei number too is erased, i was using ics firmware, i updated it to jellybean thinking it would fix the problem, but still didnt help, pls can u help me… i am from sri lanka :)

        • Kuldeep Singh says:

          As i mentioned in post there is no way to restore IMEI at home without EFS backup (maybe i didnt find it yet), go to service center.

  10. Gurlal Sidhu says:

    friend i have galaxy pop s 5570 and i am unable to backup efs or imei with any of this.what is problem in efs pro? it says phone not connected and also it says perm root for phone even i have rooted phone and all root apps running

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