The 18 year old, who joined Liverpool at under-10 level, became the club's youngest player aged just 16 years and 250 days with his substitute appearance against Hull in May 2010.
Robinson said he did not hesitate about signing a new deal when one was offered.
"I was going for my lunch and I saw Damien Comolli (director of football) on my way through," he said.
"He pulled me to one side and said the club wanted to offer me a new contract.
"I'm delighted. There was no doubt in my mind, I was just so excited the club were offering me a contract.
"I've just got to keep working hard in training. I can't just sit back on this contract. I've got to keep improving and showing people what I'm about."