The Manhattan judge who kept an alleged teen robber behind bars — telling him New York City was “sick” and tired of violent youths — had a change of heart Wednesday and granted him $75,000 bail.

Acting Supreme Court Justice Stephen Antignani told Hunter Robinson, 16, that it wasn’t “fair” that he’d become the “poster child” for the city’s crime crisis.

“This case has become the poster child for all the ills that have come to our city — and that’s not fair to you,” Antignani told the teen during the bail hearing in Manhattan Supreme Court.

“None of us should be judged on the worst moment of our life.”

Robinson, who has been locked up for nearly two weeks on charges he took part in a gunpoint robbery of a 15-year-old boy, was also assaulted in juvie, the judge said.

“It didn’t feel good, right?” the judge asked him.

Antignani made headlines for his tough stance on Robinson and other youngsters allegedly involved in gun crimes. Last week, he refused to spring the teen from lockup, while lecturing him, “We’re tired. New York City is tired” in an apparent reference to the trend in teen violence.

“You want to allegedly participate in incidents like this that dehumanize another human being? For what? If you did it, for what?” Antignani railed.

The tirade came after Robinson’s defense attorney had asked Antignani to reconsider another judge’s decision to send the teen to a juvenile detention center at his Feb. 12 arraignment.

But the no-nonsense jurist had said there was no new information at the time that would make him walk back his colleague’s ruling.

“There’s nothing good about jail. It’s not nice in there,” Antignani had warned Robinson, while noting the teen’s lack of freedom at the Crossroads Juvenile Center.

At a hearing about Robinson’s indictment the next day, the judge again rebuffed requests to set bail from both defense attorneys and prosecutors.

“I make the determination,” he had told Assistant District Attorney Edward Smith. “Not you. Not the DA’s office. I do.”

Antignani, however, struck a different tune Wednesday after reviewing letters from Robinson’s principal and teachers at Success Academy showing his “tremendous recovery in terms of his academic success.”

One of the teen’s teachers described him as a “charismatic leader” with a “big heart and a lot of compassion for other peers who are struggling.” Another teacher said Robinson was an “academic superstar.” 

Defense attorneys submitted the letters while requesting bail in the case.

They and prosecutors have previously noted Robinson’s lack of criminal history, good school record and that he isn’t accused of actually brandishing one of the firearms used in the Jan. 6 robbery.

Still, Antignani told the 10th grader: “It bothers me to my core, from someone who is as good as you, based on these papers … could’ve participated in an act so cruel.”

Prosecutors allege that Robinson was part of a violent group who lured a fellow student into a stairwell to rob him of his wallet, phone, coat and shoes. One of them pointed a gun in the victim’s face, and another brandished a gun and struck him in the face with it.

His co-defendants include a pair of brothers also accused of firing gunshots that hit an NYPD cop.

If Robinson makes the $75,000 cash bail, $75,000 insurance company bond or $75,000 partially secured bond with 6 percent, he will have a 6 p.m. curfew.

The teen has his Supreme Court arraignment on the indictment set for March 11.