Erase ALL content.

[KiiD]

Ok so I bought my iPhone 5 today how can I completely erased EVERY LITTLE piece of my information off my iphone4s?

 

[Applejuiced]

Restore it and setup as new.

 

[lelisa13p]

Turn OFF iMessage first.

 

[AppleFan91]

Most people do Settings -> General -> Reset -> Erase all content and settings. But if you are overly concerned then I would restore in iTunes and set us as a new iPhone.

 

[KandyKane]

Turn OFF iMessage first.

Definatelt turn off iMessage first!

I did a delete all content AND an iTunes restore and the buyer still got into my iMessage!

 

[lelisa13p]

Prior to the introduction of iMessage in 2011, it wasn't necessary to do anything other than wipe the iPhone. Now failure to disable iMessage has the potential of being a big problem for the seller to correct. Much easier to just avoid the pitfall.

 

[BlueKhufu]

http://support.apple.com/kb/ht2110

Erase All Content...

Devices that support hardware encryption (your 4s): Erases user settings and information by removing the encryption key that protects the data. This process takes just a few minutes.