Justin Long was 28 in Alvin and the Chipmunks when he played the character 'Alvin (voice)'.
That was over 16 years ago in 2007.
Today he is 45, and has starred in 76 movies in total, 53 of those since Alvin and the Chipmunks was released.
In Alvin and the Chipmunks, I think Justin Long looks: