How To Unlock iOS 4.2.1 on iPhone 3G and 3GS with RedSn0w 0.9.5b5 and UltraSn0w 1.2

Simple instruction on how to unlock your iPhone 3G and 3GS running on iOS 4.2.1 with RedSnow [RedSn0w] and UltraSnow [UltraSn0w] 1.2.

Jailbreaking and unlocking your iOS 4.2.1 is very simple. But before proceeding, you have to be sure that you know what you are doing or you know someone who does in case something goes wrong.

To unlock your iPhone 3G or 3GS, you need to update your iPhone modem baseband to an unsupported Apple baseband version [Baseband 16.15.00]. Baseband 16.15.00 which is an iPad baseband.

The following procedure will guide you on how to jailbreak and unlock your iPhone 3G or 3GS with iOS 4.2.1.


You do this procedure at your own risk. Please understand the consequences of updating to baseband 16.15.00.

  1. There is no way to come back down from 06.15, and there’s no hiding the baseband version from Apple. You’ll be voiding your warranty in a very obvious way.
  2. If some future baseband comes out with a critical fix, you won’t be able to update to it if it remains down in the 05.xx sequence (then again, you wouldn’t update to it if you wanted to keep your unlock anyway).
  3. Starting with FW 4.2.1 if you have 06.15 on your iPhone you won’t ever be able to restore to stock firmware (it will fail). You’ll need to only restore to custom IPSWs (then again, if you’re an unlocker you should already be doing that).

The new redsn0w 0.9.6b5 fetches the 06.15.00 baseband files directly from Apple for now (the only IPSW you ever point it at is the stock IPSW for the FW on your iPhone right now). There may be a long delay while it’s doing this (their servers are currently getting pounded).

Supported devices:

This version of redsn0w 0.9.6b5 is developed ONLY for iPhone 3GS and 3G users who rely on unlock. Precisely, This guide showing how to jailbreak and update baseband to 06.15.00 for ONLY iPhone 3GS and 3G who have unlocked devices. Ultrasn0w unlock is not yet supported for iPhone 4.

Unsupported devices:

iPhone 4 and 3GS users who don’t rely on unlock should follow the same guide but with redsn0w 0.9.6b4 to jailbreak their devices on iOS 4.2.1.

What you need:

RedSn0w 0.9.6b5 | download [Windows] [Mac]

iPhone 3G and 3GS running on iOS 4.2.1 | (If you don’t have iOS 4.2.1 in your iPhone, you can update it via iTunes.)

iOS 4.2.1 latest firmware | Download [3G] [3GS]

Latest iTunes version | download [Here]


1. Launch Redsn0w 0.9.6b5, and browse for iOS 4.2.1 firmware final version.

Wicked Sago [dot] Blogspot [dot] Com

2. Click NEXT.

3. Tick “Install Cyndia” and “Install iPad Baseband”, and then click NEXT.

Warning: If you proceed with the iPad baseband install, you won’t be able to go back to your previous baseband. Be sure that you know what you are doing, or you have someone nearby who does in case something goes wrong with the jailbreak and the install.

Wicked Sago [dot] Blogspot [dot] Com

Wicked Sago [dot] Blogspot [dot] Com

Wicked Sago [dot] Blogspot [dot] Com

4. Now make sure your device is both OFF and PLUGGED IN to the computer before you click NEXT.

Wicked Sago [dot] Blogspot [dot] Com

5. At this stage you will need to put your iPhone in DFU mode by holding “Power” button and then while holding the “Power” button, you will now have to hold “Home” button too. Now after few seconds release “Power” button but keep holding “Home” button until installation begins.

Wicked Sago [dot] Blogspot [dot] Com

Wicked Sago [dot] Blogspot [dot] Com

Wicked Sago [dot] Blogspot [dot] Com

6. After the redan0w is done working its magic you will get a jailbroken iPhone on the latest iOS 4.2.1 and the unlockable baseband 06.15.00.

Once you jailbreak your device, you can now unlock your iPhone on baseband 06.15.00 using Ultrasn0w 1.2 from Cydia.



  1. In myself inclination about unlocking iPhone4. The best way to ensure your iPhone 4 is to keeping it on the safe place and using it with knowledge. And using gevey sim for all iPhone models you could have it in a cheap price ever.

  2. Jailbreaking and unlocking your iOS 4.2.1 is very simple. But before
    proceeding, you have to be sure that you know what you are doing or you
    know someone who does in case something goes wrong.  ways to unlock iphone 3gs

  3. i have an old iphone 3G ive already jailbroken the phone, im trying to run ultrasn0w via cydia  but it keeps saying the internet connection seems to be offline, do i need a working sim please help 

  4. i already have an updated baseband 06.15.00 and iOS 4.2.1
    How do I jailbreak it ???

  5. I had my iphone factory unlock at Jailbreakhome.comsince this process did not work for me. I'm glad that my phone is now iphone factory unlock.

  6. I had my iphone factory
    unlock at since this
    process did not work for me. I'm glad that my phone is now iphone factory unlock.

  7. sir how to fix it if stuck on black screen while rebooting?

  8. Great post to share - Thanks

  9. Read This. i Gracy try so many of this spell casters when my husbands tends to divorce me because he thought i keep a secret from him before we get married. they all ask of different thing with money and i provide to each because my husband is my life and i love him so much but they all disappoint me till the court finally sign our divorce document so we go apart last 3years 2012 march 15 i packed to my new day while i was alone( within February ) i just decide to get some knowledge on how to cope with divorce and forget the memories of my past husband because i thought he had marry another woman. while i was reading online i saw how Dr ( help some men and women get all they desired including healing the sick one. i just decide to contact oshogum also and just ask him how much his work cost but replied and said it free but i most tell the word how he solved my problem if he can do it. so i promised and he sent me the name of materials that his great god demand to get man back. my friend in Norway help me get the items because i could not get the materials here in Germany and she also send it to him. after two days he told me to call my husband but his number was disconnected but he direct me to call my husband work phone that i did, once my husband heard my voice he was very happy, he asked me were i was, i told him my new house. i was so surprise to him in my house. i never believe he can ever come back again. he beg for forgiveness and true love. We both go the same court to terminate the divorce agreement. Still like i am dreaming to see Davidson came back and we live together now even expecting our first kid soon. Thanks to Well you can contact him now case you suffer any problem.

  10. I think I
    have never seen such blogs ever before that has complete things with all
    details which I want. So kindly update this ever for us.

    att iphone unlock

  11. the best way to unlock your iphone

  12. Download JailBreak 8 iOS free working here:

  13. my name are andrea loops.and i want to thank dr alexzander for saving my home and making my husband ten times rich than he was before. I was in a relationship where my partner was not paying enough attention to me, never told me that he loves me only when I asked him and I was never a priority in his life. One day I start searching for help and I heared about dr. alexzander Hightemple. He just safe my relationship. He did a spell charm to safe my relationship. Today I'm grateful to dr Alexzander Hightemple who did an amazing work. He safe our relationship and today my partner treat me like a queen. I became everything for him. Don't think too much anymore because god has sent a great spell caster who can do all things,just to see smile on the face of young lovers and family. contact him at . He is the one who will and can help you in what so ever situation you fine yourself into.
    once again i say thank you for your deeds dr alexzander me and my family are greatfull to you and your gods