Jailbreak your iPhone

Downgrade iPhone 3GS iOS 4.0 to 3.1.3 with Cydia SHSH


Apple released iOS 4.0, so as of today, Apple has stopped signing 3.1.3 restore files. That means that if you have a 3GS iPhone you cannot restore any firmware other than iOS 4. If you guys updated to iOS 4 and wanna go back to OS 3.1.3 or below here is the step by step guide to downgrade your iPhone 3GS iOS 4 to 3.1.3 or below. This hack can be attempted only for those, who saved their SHSH to Cydia Server before the release of iOS 4.0 via Cydia “make my life easier” button.

The process is very simple all you have to do is to add Saurik’s Server address to your system hosts file. This trick make iTunes thinks it is talking to Apple, it is talking to Cydia instead while the restoring process. Doing this will allow iTunes to access signatures already stored by Cydia “on file” feature. In simple words this duplicates the functionality exposed by Apple’s signature server, except using “on file” results rather than live request.


  1. This process is only for those who saved their SHSH to Cydia Server already.
  2. Read the whole process two-three times before starting the process.


How to Edit and Save Hosts file in Windows

  • Open Notepad with Administrative privileges by clicking Start, All Programs,Accessories, and then right-click Notepad and select to open as Administrator.
  • Now browse to (C:/Windows / System32 / drivers / etc) in Notepad and open the hosts file, and add the following entry to the bottom of the file.    gs.apple.com               <————

Now you navigate to files menu and save the hosts file. By doing this you changed the communication server from Apple to Sauriks Server, because your ECID is on that server. Now you can put your iPhone in DFU mode to restore back to to OS 3.1.3 or lower. Follow our previous guide Downgrade iPhone 3G / 3GS


How to Edit and Save Hosts file in Mac OS X

  • Navigate to Finder, Click to select Go to Folder… from the Go menu and Enter /etc into the input field and click the Go button.
  • Now look for hosts file, right click on hosts file and open with Text Edit, and add the following entry to the bottom of the file.   gs.apple.com <————


  • Now save the file and click on Save As.
  • Because Text Editor can’t save your system files, here comes the tricky part, in save as windows use the following settings, take a close look at the following image. asd

Uncheck the “ If no extension is provide, use .txt “ and then press the save button.

  • A host file will be appear on your Desktop, just drag and drop to /etc and follow the onscreen instructions.


By doing this you changed the communication server from Apple to Sauriks Server, because your ECID is on that server. Now you can put your iPhone in DFU mode to restore to any of the previous OS. Follow our previous guide Downgrade iPhone 3G / 3GS

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Comments ( 22 )

Have Something To Say ?

  1. Jason October 12, 2010 Reply

    when i goto C:/Windows/System32/drivers/etc i dont see any host files, where is it/what do i do?

  2. Mark September 9, 2010 Reply

    Thanks!!! I finally got this to work for my ipod touch. It was completely stuck in recovery mode with no way out (trust me, I tried every way possible and nothing worked), but with your help I actually updated to 4.0 to jailbreak it again easily without having to wait for the 4.1 jailbreak to surface.

  3. Dhruv sharma September 9, 2010 Reply

    Hi people I upgraded my iPhone 3GS. To 4.0.2 know I don’t have cydia and my cell is again locked can you plzzz help me

  4. Pinote September 7, 2010 Reply

    So I try to do Step by Step Maybe more than 100 time so Got many error so I can downgrade but shsh4.0/4.0.2 only why u post make confuge
    Becoz some guy told me noway to downgrade to 3.1.2-3.1.3 all any firmware But I do like your post every step got Many ERROR 3614 31xxxx
    I don’t know how to do but Can use Shsh file form someone else rename to my divide name THANK FOR YOUR POSTED

  5. Sunita September 6, 2010 Reply

    Hi Louis,
    Did you have your SHSH blob on Cydia or you’ve done without it. Please let me know. I’m going crazy because of this stupid OS4.

  6. louis September 1, 2010 Reply

    IT WORK WOW!!!!!!!!!!!!!!!!!

    “ gs.apple.com”

  7. sammy August 14, 2010 Reply

    worked fine for me i had iOS4.0 downgraded to 3.1.2 no problem


  8. Ghozzy August 13, 2010 Reply

    Mark Works Great On My iPhone 3GS From 4.0.2 To 4.0 Thank You Very Very Very Much Man You’r The Best

  9. mark August 8, 2010 Reply

    how jailbreak 0s4 on any ipod go on your ipod safari and add this site works mint


  10. AdrianX August 4, 2010 Reply

    oli said:

    not working
    Error Code 1600

    i had this issue also but after I re-installed OS ( XP or windows 7 ) it worked fine.

  11. oli July 20, 2010 Reply

    not working
    Error Code 1600

  12. mark July 19, 2010 Reply

    heres a good way to down grade 4.0 to 3.1.3

    Hi every1 hop gna mak u happy by helpin u fixin error 3194 when downgrade from ios 4 to 3.1.3 and it Might also worked for 3.1.2..

    I ve tried a way and it worked for me hop it ll for u also.

    IMPORTANT this ll might help in 3194 but not the 1051 ( u ll need to google it)

    I ve ben searching the net for a fixin to that stupid error for 3 days and nothin there apart from editing the hosts file nd also not working for many ..this only worked if u have ur shsh saved on saurik server ..


    1.u ll need to have ( iTunes 9.2 – – ipsw 3.1.3 — tinyumberlla the latest version)

    2.edit ur hosts file to the gs.apple.com

    3.turn on iPhone and connect it to the pc and open the (tinyumberlla) and click on advance and choose (iPhone 3.1.3) but don’tttt click on ( save shsh) u need to click (start TSS) and wait till it say connected in the box and the click on save my shsh )it should say u have ur shsh saved with cydia and importannnnnntttt note don’tttt close the program keep it onnnnnnn keep it onnnnnnn

    4.it dosnt need ur iPhone to be puttin in any mode keep it the way as it is

    . 5.open iTunes and click on restore with shift and choose 3.1.3 software and everything should be alright ..

    6.if everything went fine u ll need to search for the error 1051 bcz u ll face it at the end of the restoring(google it)

    Hopefully it will help .simple thank ll do the job ” if it worked ”

    ..enjoy everyone. mark

  13. Malik July 19, 2010 Reply

    Hey I gat 3g 16g bought from a guy locked with atnt with 4.0 5.13.01,successfully downgraded to 3.1 jailbroke and unlocked(redsnow 9.5,ultrasn0w)wondering if I can upgrade to 3.1.3 and unlock again.didn’t have to do any tricks to downgrade

  14. angelie July 18, 2010 Reply

    i want to downgrade my iphone 3Gs. from ios4 to original version

  15. Sapiee July 18, 2010 Reply

    I one downgrade my 3GS

  16. Cab July 17, 2010 Reply

    You can use tinyumbrella to check if your blobs are on cydia. Just download the program run TU and it’ll search find and download your blobs if they are there.

  17. jeff June 24, 2010 Reply

    not working….. i had saved my SHSH….. itunes says that it is an incompatable firmware…. do i need the older itunes? i’m running itunes 9


  18. GreYFoX June 24, 2010 Reply

    @Adam Solomon
    this process happens automatically you don’t have to produce any steps for it to happen, there are only unlucky few who haven’t their shsh blobs saved

    if you are one of them then sorry there is not hope

  19. Edward Donaghey June 24, 2010 Reply

    Hey lokesh, the only thing i would suggest is to put the iphone in dfu mode and restore through itunes using the lastest iOS

  20. Jake June 24, 2010 Reply

    Does anyone get this work ? Gives me always an error: “This device isn’t eligible for requested build”. SHSH’s for 3.1.3 are in safe in Saurik’s server for this device.

  21. lokesh June 23, 2010 Reply


    i have an iphone3G(S) which is of 3.1.2. (7D11),….i had accidentally upgraded to 3.1.3 through itunes ….
    my iphone got stuck up to “recovery mode” and on that “no sim card installed” is displayed on the screen …

    so, what should i do…

    PLZZ HELP ME!!!!!!!!!!!

  22. Adam Solomon June 23, 2010 Reply

    Is there any hope for those who haven’t saved their SHSH to Cydia Server?

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