Convert 3GP to MP4

What 3GP is

3GP was defined by 3GPP, the group behind 3G mobile networks, as a light format for phones built on the same base as MP4; CDMA phones used its sibling, 3G2. Phones from the early and mid 2000s typically filmed at 176 × 144 or 320 × 240 pixels, around 15 frames a second, with H.263 or MPEG-4 video and AMR sound: 8 kHz mono, made for speech. A minute of it was often under a megabyte. Later phones moved to H.264 and AAC.

The same format carried video messages (MMS), so clips people sent each other are often 3GP too. Many current apps, editors and upload forms no longer take them, while an MP4 opens everywhere.

What happens to the picture and sound

With High, every picture becomes H.264, whatever the phone used. As it is would copy H.264 and MPEG-4 pictures instead, but MPEG-4 copied into an MP4 is the older kind many players skip, so High is the simpler choice for phone clips. Frame rates stay as the phone recorded them, often 15 or fewer, so motion looks as it did on the phone.

The sound always becomes AAC, since Octoolo does not keep AMR in an MP4. It stays 8 kHz mono and still sounds like a phone call: AMR kept only the range of the voice, and converting cannot bring back the rest.

Do not be surprised if an MP4 is a little bigger than its 3GP. AMR squeezed the sound into about 12 kbps, and AAC gives it more room without making it sound better. For a lighter file, set Bit rate to 64 kbps under More settings.

Getting clips off an old phone

Most phones of that era kept videos on a memory card, often microSD, or in internal memory you could reach over USB or with the maker's PC software. If the phone no longer starts, its card may still read in a card reader. Backups made with the phone maker's software may hold the clips as .3gp files too.

Once they are on your PC, drop the whole folder: Octoolo takes up to 500 files per drop (Add more for the rest), converts several side by side, and leaves the originals untouched. Each MP4 keeps the name of its 3GP, so nothing gets harder to find. Copying in File Explorer keeps each file's Date modified, so sorting by date still puts the clips in the order they were filmed.

Voice notes and other files in the backup

Old phone backups hold more than videos. Voice recordings were often saved as .amr files, and the converter lists those too when you drop a folder, since they are sound files. Turned into MP4 they would become videos with no picture, which is rarely what you want.

Remove the .amr rows with their × button before converting, and do the voice notes separately in Converters' Convert audio, where MP3 is the obvious choice: AMR to MP3 walks through it. Ringtones saved as MP3 are listed as sound files too and can go the same way, while photos in JPG are not listed at all. The originals stay in the backup folder either way.