Later, he appeared outside the bail hostel and stayed silent as he waved to photographers and reporters.
The Islamist preacher qualified for automatic release after reaching the halfway point of a five-and-a-half-year sentence, when time spent on remand was taken into account.
For the rest of the sentence period, he will be subject to a strict supervision regime, with around 25 licence conditions.
Chris Phillips, former head of the national counter terrorism security office, said Choudary's release is a "concern" and will exhaust the resources of police and security services.
He told Sky News: "It will be difficult but this is a long-term issue.
"It's not something you can keep him on tab for a day, a week, a month.
"But of course we are talking about a long time into the future and in six months, 12 months' time he's still going to be a concern and that is a large amount of resources for the police and security services just don't have."
SKY News.
