Tip o’ the Week: Sync iPhone on Two Computers

I don’t know if you have tried this (I have), but if you attempt to sync your iPhone with any computer other than the one you originally synced with your iPhone, you will receive a warning that your iPhone is “synced with another iTunes library.” Your only choice at this point is to “Cancel” the operation or “Erase and Sync” because your iPhone can only be synced to one iTunes library at a time. Or CAN it?
Thanks to a set of most excellent instructions from the Shiny Things blog of Andrew Grant located here, you can sync your iPhone with one or more additional computers. Read on to learn more!
As I said before, Andrew Grant has posted excellent instructions to sync your iPhone with computers other than your original. Rather than go into repeating all the details of this method, I will instead provide an overview of the steps that Andrew has put together and refer you to his blog for the detailed, play-by-play so you can do this yourself!

In order to sync to more than one computer, there are some needed modifications to iTunes that will then let you sync different data on your iPhone with more than one computer. For example, you may want to sync contacts and calendar items on your work machine, but sync all your media (songs, podcasts, movies, etc.) on your home computer.
According to Andrew Grant (thanks for your hard work on this, Andrew!), the first thing you want to do is backup “iTunes Music Library.xml” and “iTunes Music Library” (Tunes Music Library.itl on a PC) to a safe location on the computer you want to sync with. You will modify these files so you can safely sync with this computer.
On the computer you currently sync your iPhone with, find your iTunes Library ID. Andrew has posted instructions on how this is done. The idea here is that you want your second machine to have the same iTunes Library ID that the original has so your iPhone won’t know the difference. Again, this process is explained in detail by Andrew.
Once you have followed all of Andrew’s instructions, you should be able to plug your iPhone into the second machine, select “Manually manage music and videos”, you will NOT be prompted to erase any data, and you are ready to roll! Again, special thanks to Andrew Grant for posting this handy tip on his blog. Make sure you go to his blog and follow the steps precisely.
Disclaimer: Tip o’ the Week makes no guarantee, express or implied, that any tip found herein will be new or particularly useful to the reader (and please remember that any time you are being sneaky with your iPhone and syncing, you do so at your OWN risk!)

















October 18th, 2008 at 3:50 am
jailbroken phones can have an app called SwapTunes which is all on the phone. And one step.
October 18th, 2008 at 1:32 pm
this is a great tip thanks
October 19th, 2008 at 3:28 am
thanks for this post. I have been trying to figure a workaround for this for a while now.
October 19th, 2008 at 9:58 pm
Not sure why this story keeps making the rounds. At least with iTunes 8/iPhone 3G this is possible without any tricks. I sync my iPhone contacts/calendar with my mac and music/podcasts with my PC. There has never been a need to hack anything for that.
October 20th, 2008 at 1:40 am
Jason — I think the workaround is for syncing 2 music libraries together. I do mail / contacts / bookmarks / photos from one machine and music / applications from another, but if memory serves I get the warning if I try to enable music library syncing to the “business” computer instead of the “fun” computer…
October 20th, 2008 at 9:20 am
Will the trick allow you to sync your music both in your home mac and your work PC. people has explained how the manage to sync calendars here and music there but not just music in both places. will all your music get transfered from one place to another?
November 8th, 2008 at 2:15 pm
This “hack” does NOT, I repeat, does NOT work with the latest iPhone version and/or iTunes 8.0.1. After following the instructions very carefully I still receive the same message that the contents of my iPhone will be erased if I choose to proceed. Certainly there has got to be a way around this.
November 22nd, 2008 at 1:11 pm
I tried this hack as well and am sad to report that it doesn’t work. Anyone found another way to sync two computers with our iPhones?
November 24th, 2008 at 5:31 pm
I tried to use this but when I use a hex editing program to search for the string it says it is not found. My scenario is a little different, I formatted my computer and would like to sync my iphone again. It won’t let me without erase and sync. I saved the .xml file before I formatted so I believe I should have the string I need to replace in the files. I could be wrong but I still cant even get it to find the string from the current itunes in the .itl file. any help with my predicament would be greatly appreciated.
December 10th, 2008 at 7:31 pm
Geoffery and Jason above are wrong. The hack works fine. Here it is quickly: Change the library id of all your iTunes libraries so they are the same. Pick the id of the iTunes library you already sync to.
In order to do this, you use a text editor for the .xml and a hex editor for the binary file. Easy.
December 11th, 2008 at 8:57 pm
You are simply wrong, JHN. Completely. This WILL NOT work with the latest upgrades. The HEX has been CHANGED and no longer CONTAINS the matching hex for the 16 digit library ID number. You can change the XML all day, but you cannot change the hex. This WILL NOT WORK for updated Itunes. Forget it.
December 11th, 2008 at 8:58 pm
Also, the MOMENT you open Itunes after changing the 16 digit XML on Updates Itunes…it REVERTS the number back to the original. THE ONLY way to make this work is to REVERT Itunes back to 8 or below. Updated ones? Forget it. Waste of time.
December 19th, 2008 at 8:25 pm
Merid are you sure? Jim did you verify this?
December 31st, 2008 at 3:17 pm
Hey all – I would love to be wrong about this hack not working…I just deleted my music from my iPhone again! (user error).
I wish there was just a simple way to sync up with two computers…
January 17th, 2009 at 6:27 pm
I have changed the iTunes music folder to a different one as opposed to the Default (My music/iTunes/…) on my work PC. However my home PC is default set by the iTunes installation. Does this make any difference. I tried chainging the Library code in the xml and hex on my home pc to reflect my office pc, but the hack does not work. I have iPhone 3G(2.2) and latest Itunes 8.0.2.
July 28th, 2009 at 7:23 pm
I have actually created a small tool (PC only) that does all the work for you feel free to download it here: http://www.megaupload.com/?d=6QKYMDEZ
and if you like it, toss a buck or two my way
August 6th, 2009 at 2:52 am
you rock rey, just foudn it on cydia, none of this itunes hacking nonsence
September 16th, 2009 at 5:10 am
destro: How about support for iTunes 9.0?
October 13th, 2009 at 10:15 am
Look guys, with the 3gS it works jst fine itried to sync with my mac and pc(calendar, contacts)
October 19th, 2009 at 4:21 am
destro,
This is wonderful and the most useful stuff every created for iphone/ipod
can you please update the utility to support iTunes 9x also? itunes was 9x was released very recently.
thanks