John Joseph Sullivan, 33, of Wharncliffe Road, Southampton, quietly spoke at Southampton Crown Court on Friday to plead guilty to each charge as they were read to him.
He has pleaded guilty to a host of sex offences between 2023 and late 2025, including multiple charges of taking and distributing child abuse images.
He also admitted sexual assault of a child under 13 in 2023, and voyeurism.
In addition, the charges stated he had extreme pornographic material.
The case has been adjourned to April 22 for sentencing.
He has been remanded in custody.