What a difference a year makes for Charli XCX.

12 months ago, the British “It Girl” was about to drop her album called “Brat,” which would kick off a summer filled with “Brat” vibes and turn her into a pop-culture sensation.

Twelve years after her debut LP, 2013’s “True Romance,” she was a breakout pop star in her early 30s — middle age in pop years — doing collabs with Billie Eilish, appearing on “Saturday Night Live” and getting seven Grammy nominations, including a prestigious Album of the Year nod.

Nearly three months after winning three of those Grammys — including Best Dance/Electronic Album for “Brat” and Best Dance Recording for “Von dutch” — the 32-year-old singer headlined the first of four sold-out shows at Brooklyn’s Barclays Center on Wednesday.

After a co-headlining concert with Troye Sivan at Madison Square Garden last September, this time it was all her. And she was coming in hot off two Coachella performances that had celebs such as Timothée Chalamet and Kylie Jenner bopping to her beats.

The buzz was definitely in the air on Wednesday night for one of the hottest tickets of the year, with concertgoers wearing their most “Brat” fits, many in “Brat” neon green.

And it didn’t take long before Charli XCX launched into two of that album’s biggest hits in “360” and “Von dutch.” Body-rocking across the dark, smoky stage in her trademark black shads, she transformed Barclays Center into a Brooklyn warehouse.

Indeed, this felt more like a rave than a concert, a sweaty club instead of an arena.

“Night one baby! You f—king ready to party with Charli XCX?” she exclaimed.

No doubt — there was an infectious party atmosphere that made the show feel intimate and the singer feel accessible.

It was just Charli XCX on the stage for the entire time — discounting the cameraman filming her — and she owned it, from the throbbing “Club Classics” to the tender “So I,” her tribute to her late collaborator Sophie.

She may not be the best dancer, nor the best singer, but she has — as the kids say — a vibe.

And there was an unchoreographed feel to it all that gave the show a loose and lively feel, as if Charli XCX was just living in the moment right along with her thousands of fans.

But it also felt a bit bare onstage with no background dancers and such minimal production that it seemed a little, well, cheap.

Plus, with no visible band, it seemed as if Charli XCX was singing to track most of the time. That might have been OK for Terminal 5 or Brooklyn Steel, but it felt underwhelming in a big arena like Barclays Center (where she will return Thursday, Saturday and Sunday).

And Charli XCX could’ve used at least one surprise guest among her many collaborators. But there was no Troye Sivan on “Talk Talk,” no Lorde on “Girl, so confusing,” no Billie Eilish on “Guess.”

Still, that hardly seemed to matter by the time she opened her encore with “party 4 U” — because she had delivered just that for her fans who came to party with her.

While Charli XCX was clearly living in this moment with a set leaning heavily on “Brat” and its deluxe edition — forgoing earlier hits such as “Boom Clap” and her Iggy Azalea collab “Fancy” —

she closed the night with “I Love It,” her 2012 hit with Icona Pop.

And love it, they did.