What is the difference between kingdom of heaven and kingdom of God?

[TonyChanYT]

Matthew was the only one who used the term kingdom of heaven, Matthew 13:

11 He replied, “You have been given the opportunity to know the secrets of the kingdom of heaven, but they have not."

Parallel account in Mark 4:

11 He said to them, “The secret of the kingdom of God has been given to you. But to those outside, everything is in parables."

Another parallel account in Luke 8:

10 He said, “You have been given the opportunity to know the secrets of the kingdom of God, but for others they are in parables, so that although they see they may not see, and although they hear they may not understand.

Both terms mean the same thing. See What is the kingdom of God?. Even in English today, some people say "good Heavens"; some say "good God"; Macmillan:

good Heavens/Lord/God/grief/gracious
used for showing that you are very surprised, angry, or upset

Even within the gospel of Matthew, he used the terms interchangeably 19:

23 Then Jesus said to his disciples, “I tell you the truth, it will be hard for a rich person to enter the kingdom of heaven! 19:24 Again I say, it is easier for a camel to go through the eye of a needle than for a rich person to enter into the kingdom of God.”

 

[Bob Estey]

Matthew was the only one who used the term kingdom of heaven, Matthew 13:


Parallel account in Mark 4:


Another parallel account in Luke 8:


Both terms mean the same thing. See What is the kingdom of God?. Even in English today, some people say "good Heavens"; some say "good God"; Macmillan:


Even within the gospel of Matthew, he used the terms interchangeably 19:

I suspect they are the same thing, though I haven't studied the subject.