Does Restore to Factory Settings wipe everything?

I'm planning to trade my old iPhone in to GameStop, but I still have a lot of Facebook, Twitter, etc.accounts logged in and don't know that if I log out that it will solve everything. I don't want to take the risk of any future owners being able to access my accounts, so if I restore to factory settings, does that completely wipe that information from my phone?

Yes. Use the Restore option in iTunes.

  • Will i lose my iphone contacts if i restore to factory settings? I have to restore to factory settings because of a really annoying problem related to downloading apps, will i lose my contacts if i restore to factory settings?
  • When you restore your iphone, does it wipe out everything from your itunes? I understand that it will wipe out everything from your physical iphone, but i was wondering if it would wipe out everything on your itunes account to, such as music.
  • My iphone wants to restore to factory settings? Question is should i do it? it states it will erase all data and update so i'm not sure if i want to risk it incase it worsens the situation. i've updated itunes and tried again with no luck. Its annoying as i can't sync any cds onto it and it can't update… Is it worth the risk? Or should i just leave it and keep it as it is as i have no other problems with the phone.
  • My iphone 3gs won't restore to factory settings? I bought an iphone 3gs for $50 from my friend, it worked fine except i had to restore it. It automatically updated the IOS but when it finishes restoring it gives me a message that says something like: "itunes could not restore your device due to an unknown error(-0)." any idea on how i can fix it? Or does this mean my iphone is obsolete and will no longer work?