Free 3GP Video Converterquestion

I copied many 3GP videos from my old computer.
It's about my family life records.
I found that I can't play them on IOS
My wife told me that I should use 3gp file converter to shape it out.
I'd like to hear your advice
Which converter is better?
Thx for your help.

I copied many 3GP videos from my old computer.
It's about my family life records.
I found that I can't play them on IOS
My wife told me that I should use 3gp file converter to shape it out.
I'd like to hear your advice
Which converter is better?
Thx for your help.

Hi, Do you mean that you can not play the videos via AirDroid on web.airdroid.com?

Is there any error msg when it failed to play? Would you pls send us a screenshot of it?