De Gea has received much criticism since his arrival at Manchester United.
"You have to find your own way of being a goalkeeper," said Hart.
"You don't have to be 6ft 8ins and able to fight 10 people at the same time.
"He (De Gea) has had great games where he's done things others couldn't do.
"There are pros and cons with every goalkeeper and the majority of the time, the pros outweigh the cons."