Downgrading iOS 4 to 3.1.3

Every time Apple releases a new firmware, they stop signing the older one, which means you technically can’t downgrade to a previous firmware by restoring. Fortunately, if you have your ECID SHSH on file on Saurik’s servers, then you might be able to downgrade your iPhone from iOS 4 to 3.1.3 or earlier.

The trick is to make iTunes believe it is requesting a signature from Apple’s servers while it will actually be talking to Saurik’s servers.

Downgrading from iOS 4 to 3.1.3 does require you saved your SHSH on Saurik’s servers. If you haven’t, then you can’t downgrade.

Downgrade from iPhone iOS 4 to firmware 3.1.3

Step 1 for Windows: Make sure you are logged in with administrator privileges. Launch Notepad and navigate to C:/Windows/System32/drivers/etc. Add the following at the very bottom of the file:

Now save the file back where you found it.

Step 1 for Mac: In Finder, select Go To Folder, and enter /etc. Search the hosts file and right click on it to open with TextEdit. Add the following at the very bottom of the file:

Click Save As to save the edited file on your desktop. Name the file hosts, and make sure to uncheck the box that says “if no extension is provide, use .txt”.

Now drag and drop this edited file to /etc.

Step 2: Download the firmware you want to downgrade to from here.

Step 3: Put your iPhone in DFU mode. Launch iTunes and plug your iPhone in. Press and hold the home and and sleep button together for 10 seconds. After exactly 10 seconds, release the sleep button while still holding the home button. Keep holding the home button until iTunes tells you it has found an iPhone in recovery mode.

Step 4: Now hold the Option key (Mac only) or Shift key (Windows only) while clicking the Restore button in iTunes. A dialog box will pop up and you’ll be able to choose the firmware you downloaded in step 2.

Step 5: At this point, some of you will be fine. The iPhone will restore without any problem. However, some of you might end up in recovery mode again. It’s ok. We just need to kick the iPhone out of recovery mode. To do so, download and launch iReb for Windows or iRecovery (both Mac and Windows).

Welcome back to 3.1.3!

[image Life Hacker]

  • Mir Suleman Talpur

    It was a Bit Tricky but eventualy Did It Successfully.
    Can I update It Back To 4.0?
    I used Spirit To Jailbreak and Unlocked By Ultrasn0w.
    Plz Reply.

  • Alex

    @Mir Suleman Talpur….YES you can update back to iOS 4 but it won’t be jailbroken or unlocked. Twitter messages from MuscleNerd and Comex have pretty much confirmed that they will be a userland jailbreak for the iOS 4 here soon……go on Twitter and read what MuscleNerd and Comex have to say about it…….

  • hideous

    your article is mostly right. you do not have to have your SHSH file on sauriks servers using this method

    it does require a few lines using the Terminal or Command Prompt.

  • Thefallen

    Been there, done that. iRecovery worked for me for boot up.

  • kralj

    for MB or MC serie.

  • boki

    does this work for the new bootrom too? the 6.***.2??

  • Shan

    ive got a 3GS (old bootrom) running ios 4, and I want to downgrade back to 3.1.3. i have updated my host file with whenever i go to do the restore in itunes (9.2), the restore fails whilst its trying to verify with apples server. it appears it doesnt try to look for saurik’s server where my ECID is stored. Any suggestions?

  • maps

    i have the same exact case as Shan, have an mc model but have verified that it is an old bootrom, used to be jb with spirit, someone ugraded me to ios4 and now i wanna downgrade and re-jb but fixing host file doesnt seem to do anything, still does not verify and will not accept the 3.1.3

  • Carl

    SHSH on Saurik

    If I did not save my SHSH on Saurik before upgrading to v4, can I downgrade to 3.1?

  • vern

    correct me if im wrong but in the host file dont you put thats what i have in host from when saurik posted from beginning. did it change please let me no if been updated

  • thefallen

    It works on new bootrom.

  • kupal

    can i downgrade iphone 3gs on ios4 with new bootrom? without shsh

  • Tony

    Hey Seb can u plz specify in which file for windows should i add saurik’s server ?? thank you

  • Z

    @Thefallen Can you please specify what phone. Wanted to give iOS4 a quick peek, but have new iBoot on 3gs.


  • John

    Thank Sebastian. I love when you post step by step instructions, saves me some time googling things! Off to downgrade and unlock.

  • EB

    where is the ipsw file(s)
    when I download and extract the firmware for 3gs, I see lot of dmg files. How am I supposed to load that in iTunes???

  • dont extract the file. If you’re on a mac… use another browser other than safari, since it’ll auto mount the disk image.

  • minifender

    I just did it!!! works great!!! for all of you that have a 3GS (MC MODEL, NEW BOOT ETC ETC) i just downgrade from 4.0 to 3.1.3 😉

  • John

    Seb, sweet, thanks. Slight pain in the ass getting it out of recovery mode, but I finally got it switching over to the Windows side of things. Jailbroken again, no problems (I had to download iTunes 9.1.1). Now if only the jailbreak for my iPhone 4 would come out.

  • Coach

    Minifender – did you have your ECID SHSH on file with Saurik’s before you originally upgraded to 4.0?

  • thefallen

    iPhone 3GS


    Z said:
    @Thefallen Can you please specify what phone. Wanted to give iOS4 a quick peek, but have new iBoot on 3gs.


  • thefallen

    No SHSHs saved, forget it…


    kupal said:
    can i downgrade iphone 3gs on ios4 with new bootrom? without shsh

  • Coach

    thefallen – I have 3GS and upgraded to v4 but can no longer access webbased work e-mails due multiport config and tracking cookie on companies end. v4.0 is sensitive to that while 3.1.3 was not. I never saved ECID SHSH on file with Saurik’s or Cyndia for that matter. Am I out of luck?

  • Z

    @ Thefallen Thanks bud. What made you downgrade? Didn’t like the new look?

  • thefallen

    unfortunately yes

    multitasking sucks, i prefer Backgrounder from Cydia along with SBSettings

  • Z

    @Thefallen Try backgrounder along with circuitous or dock (those two are similar, one is free, one is paid with prettier ui) or proswitcher. Good news about the downgrade, gives me a project for the night.

  • Coach

    Will jailbreaking the phone make any difference (allow for downgrade without saving shsh prior) when that becomes available for v4 (if it isn’t already)

  • thefallen


    each OS (i.e. 3.1.2 or 3.1.3 or iOS4) has its own SHSH Blobs. If you dont have the shsh’s for 3.1.3, you can’t go back from iOS4 to 3.1.3. Now… you can use Firmware Umbrella (google it) to backup the SHSH Blobs for your CURRENT OS (i.e. iOS4).

  • Coach


    Thank you, much appreciated. Thats leaves with one Q, the only reason I would save my iOS4 shsh would be for future use as this v4 shsh save will not help me with my immediate need to revert back to 3.1.3 right?

  • thefallen


  • Kris

    “This device is not eligible for the requested build”.


  • Boyo

    Thanks for this article, I think IOS 4 is Apples equivalent to Windows Vista since my iPod has only given me one new feature, slown down, and is not compatable with most of my apps (until the updates come out).

    IOS4 is NOT WORTH the bandwidth, the time, or the frustration.

  • donex96

    Hi guys, I need enlightment here.

    I have two iphone one 3g 3.1.3 alrealy spirit jailbroken and 3gs iOS4. If I save my shsh of my 3g 3.1.3 on cydia can I use it to downgrade my 3gs iOS4 to 3.1.3 ??? or the shsh is one phone specific code ??

    One more question, for my 3g I havent saved the shsh on cydia, since I have cydia already, can I save it through cydia directly not using such as autoshsh ???

    Many thanks, Kind regards,

  • I’m wondering.

    I have the early iPhone 3GS with 3.1.2 on it.
    If I want to try out 4.0 but be sure I can go back to 3.1.2 and still Jailbreak and Unlock.
    what would be the safest way to do this?

  • Edgardo

    Hi, I have a jailbreak and unlocked iphone 3g on IOS 4 and I want to downgrade to 3.1.3. What step I need to follow? I jailbreak with ultrasn0w.

  • Edgardo

    opps I Jailbreak with redsn0w_0.9.8b8-5.

  • SteveP


    I think you can thru Cydia. Click the link above that tells you how to save your SHSH.

    Help question:

    The instructions page says if I have iPhone 3G then I don’t need to worry about having saved my ECID SHSH. If that’s the case, then can anyone point me to the page with instructions on how to downgrade iPhone 3G from 4.0 to 3.1.3? The instructions on this page involve 3GS and devices that require having their blobs saved already.

  • SteveP

    I went ahead and tried the above steps anyway. BUT step 4 didn’t work! No dialog box popped up allowing me to choose my firmware. Instead, a download and update box popped up. After clicking it, iTunes wanted to install 4.02 from the server. I tried this 2 more times using the shift key (I’m windows Vista), and no go.

    Does this mean step 1 didn’t work? i checked that too. By the way, all the lines in the hosts file start with this symbol: #

    Am i supposed to insert that (#) at the beginning of the line so it’s like this?: “#”?

  • Applebits

    For whatever reason, I couldn’t get TinyUmbrella to work due to something using port 80 that I couldn’t find. Did this process, (Thanks, Sebastian!), and I’m back from 4.1 to 4.0.1!
    I did have my SHSH’s saved from 3.1.3 on up….which was awesome.
    And the RecBoot was necessary. But the upgrade to the 4.1 (which was on purpose so I can sell my phone), did change my b/r to 5.14.02 and it stayed there.
    Gotta love these hacks….. 😀

  • Help!!…. I got the the iphone4 on 4.0.2 version is there site that can jail break it plz??????? Cheers

  • Pozzdonnz

    So My Friend Told me He Can use Another Shsh blobs From another divide For bypass To suarik server so that true ????

  • emad

    i don’t really know how many people are fucked up in their head and dump ass and stupid because i just have done downgrade my 3G from 4.1 to 3.1.3 after 3 days sleeping at 5 in the morning without using that method above [ no offence to the guy how put in that method] at least he tried to help. But im talking about the useless people never answer my post, anyway im giving guys a great news for the 3G owners, who want to get back 3.1.3 after bad experience with ios 4.0 or 4.1. Is very easy who is really interested just ask me and i will tell how to do it without any more hasle download stuff and reseach on net.

  • bononoy

    emad, Im interested, Pls tell me how. I have 3G IOS 4.2.1 baseband 6.15.00. jailbroken by Redsn0w and unlocked using DiskAid because my WIFI dont work anymore after jailbreak. I only need to get my WIFI to work so Im hoping downgrade will help without locking it again. Maybe you have solutions in mind to share. TIA

  • Kevin

    it doesnt work i cant save the key back in hosts it says access denied what do i do?