After teasing iPhone 3G owners who can’t wait to unlock and free the smart phone device with a demo video of Yellowsn0w, the ultimate utility for unlocking iPhone 3G, iPhone Dev Team is finally releasing the Yellowsn0w for free public download. Contrary to previous warning that Yellowsn0w may only support up to iPhone 3G with baseband 2.11.07, the released Yellowsn0w does indeed work with (in fact, exclusively) iPhone 3G firmeware software version 2.2 with baseband 02.28.00.

Thus to use Yellowsnow to unlock iPhone 3G, you have to upgrade to iPhone software version 2.2 using iTunes and then use QuickPwn to activate and jailbreak the iPhone 3G. The application is a small daemon that is launched on boot. It injects the payload at boot and also whenever there is a baseband reset. There is no notification or GUI, except that the third-party SIM now works.

Everybody can download, install and add Yellowsn0w through Cydia or Installer sources.

Cydia source:
Installer repo:

Yellowsn0w version 0.9.5 0.9.4 0.9.6 is now released.

Some details of on usage instruction and troubleshooting of Yellowsn0w as posted on

  • There is a known issue with SIM cards that have STK (SIM Toolkit) application menus. These menus are usually items such as “top up” “get credit” “lotto numbers” etc. These menu items confuse the application sometimes. Removing and reinserting the SIM once after reboot (give it about 10 secs after you see the slide to unlock widget) fixes this issue. Better fix is in the work.
  • For those of you using SIM cards without STK menus, the application has some optional arguments that will make the unlock much faster for you. So either experiment on your own (use “yellowsn0w -h” for usage) or wait for a customization writeup.
  • After you install yellowsn0w via Cydia, you should return to the Cydia main menu then reboot your iPhone with the 3rd party SIM installed. Wait for the slide to unlock screen, then wait 10 or 15 secs more. If you don’t see your carrier name pop up, then remove your SIM, reinsert it, and wait 10 secs more.This is the step to be worked to eliminate next.
  • If you are in the U.S. and are trying this with T-Mobile, you must turn off the 3G switch in Settings.

    For unlocker using Yellowsn0w 0.9.1 or 0.9.0, you can make it much easier by adding the line -q right after the /usr/bin/yellowsn0w line in /System/Library/LaunchDaemons/org.iphone-dev.yellowsn0w.plist (this is advanced tip until somebody make a boosprefs type of tool for it). The -q option is now deprecated in 0.9.4 (it’s now always in quick mode, unless you use the -l option for long mode).

  • No PIN support yet. iPhone Dev Team is still working out the flow for SIMs with PINs enabled. Please disable any PIN you may have on that SIM before trying yellowsn0w, for now.
  • The unlock will silently quit on anything other than baseband 02.28.00. It detects the wrong version and just quits to avoid any damage. Please double check your Modem Firmware setting in Settings->General->About.

Yellowsn0w is also easily uninstallable and completely removable through Cydia, the command line, or iTunes. Yellowsn0w currently is in beta phase with version 0.9, so those who use it is at own risk.

Update: Yellowsn0w has been replaced with Ultrasn0w.