J'ai trouvé la solution, pour ma part j'ai libéré 3,7 go sur mon Iphone 5 (ios7)
voici la source : https://discussions.apple.com/thread/5323455?start=15&tstart=0
Firstly you DO NOT have to do a factory reset / wipe device, it is simply not required to get the space back!!
Mine had 3GB and I just got rid of it all, here is how:
METHOD ONE:
- Make a backup in iTunes
- open iBackupBot (Google it)
- Go to the relevant backup
- Click on Multimedia File Manager and click on the other Multimedia files tab
- Sort by filename by clicking the Filename tab
- Find MediaDomain/Library/SMS/Attachments and highlight all of them, then press delete. You can also click to export to a folder of your choice, if you want to save them that is.
- Then go to System Files>MediaDomain>Library>SMS>Attachments
- They will be all listed here, highlight them all and press delete
- Then just restore that backup using iTunes!
Tadaa! Space recovered, your messages are still there but without the attachments! METHOD TWO:
- Backup your device in iTunes and then to iCloud
- Go to Settings>iCloud and toggle Documents & Data to OFF
- Then do a 2nd backup to iTunes and iCloud
- Then restore the device from iCloud and the message attachments should be gone, turn Documents & Data back on again in the settings
PLEASE NOTE: Method two is a much longer process but some users may feel more comfortable with this method.
P.S You may want to make two backups in case you get any of the above steps wrong, but it is simple to follow the above and not do anything wrong!
P.P.S You could also just go through every single conversation and delete the attachments one by one, but if you have hundreds or thousands of attachments, this will take a VERY LONG TIME!!!