Became widely known for his role as Crazy Steve on Nickelodeon's Drake & Josh and later as Spencer Shay on iCarly.
He studied at improv and theater at the the UC Santa Barbara and the Groundlings school in Los Angeles.
He played the starring voice role in the animated series T.U.F.F. Puppy.
He has a sister named Liz Trainor.
He co-starred with Jennette McCurdy in the 2012 Nickelodeon TV movie Best Player.