Days after his Super Bowl video went viral, the British hairstylist Chris Appleton wasn’t exactly sure why it captivated so many people.

The 39-second Instagram post shows Jennifer Lopez, Mr. Appleton’s client, on the field minutes before she hit the half time show stage. Mr. Appleton is taking his brush to her springy blond hair for one last preperformance check. The intimate scene has been viewed by millions.

“After that video, so many people — even some of my mates, who don’t recognize hair — were talking about hair,” Mr. Appleton said. “It’s as if all of a sudden they’ve put on my glasses and see hair how I do — its energy and possibility.”

Mr. Appleton has accumulated a collection of these iconic hair moments. His clients are a mix of megastars and up-and-comers. Dua Lipa’s sculptural platinum-with-black-roots ponytail for the Grammys was his. Mr. Appleton did Ms. Lopez’s half up-do in September when she walked the Versace runway in her signature green jungle dress. The ankle-grazing braid she twirled in the “Te Bote 2” video was his work.

Mr. Appleton is also Kim Kardashian West’s go-to stylist and was the architect of her wet-yet-glamorous hair at the Met Gala last year.

Over the past few years, Mr. Appleton, 36, has become one of those hairstylists-who-works-with-celebrities who now has thousands of fans of his own. His Instagram feed is a mix of energetic behind-the-scenes video and images of him and his clients.

Social media has enabled his stardom, but it isn’t the foundation of it. Ms. Lopez has described his artistry and attention to detail as reminiscent of the acclaimed hairstylist Oribe Canales, who died in 2018.

“We immediately understood each other,” Ms. Lopez wrote in an email. “That chemistry is so important.” His youthful and modern sensibilities make her “feel beautiful and current,” she said.

For the Super Bowl, he and Ms. Lopez tested three styles over six days of rehearsals. But they landed on her final look by accident. For a filmed rehearsal, Mr. Appleton curled her hair with a smaller iron than usual for a little extra hold. Because of the Miami humidity, though, the curls just wouldn’t loosen.

“Never in my life had I seen hair do that,” Mr. Appleton said. He and Ms. Lopez agreed the hair was way too tight. “But after the filming, people kept coming up, like: ‘J. Lo, you killed it’ and ‘That hair!’ Her choreographer. Her manager. I realized then people love the bounce.”

For the big day, he curled her hair tight again, but after brushing it out, he used a large curling iron to create a looser wave that would still deliver a spring. “I’d told Jen, ‘I want this hair to dance with you,’ and it did.”

Mr. Appleton’s successes don’t preclude self-criticism, however. “When I watch the performance, I’m like: ‘That flip could’ve gone back in place. That moment could’ve had more movement,’” he said. “I always have to be careful that I don’t get OCD.”

When Mr. Appleton works, it’s as if each hairstyle, no matter the client, is an opportunity to be emotionally impactful. Not necessarily by hair transformation — most clients won’t go platinum or chop long locks into a short bob. But when a woman sits in his chair, he is inquisitive and chatty. And through that connection, he identifies just how far he can push so that she can, in the end, feel not only pretty but also renewed.

“Even if it’s small, like dressing up their baby hair or an interesting placement of a ponytail,” he said. “People are usually open to changes. It’s just that most of the time, no one’s asking the right questions.”

Mr. Appleton grew up in Leicester, an hour train ride north of London. “When I was in school, people would mock me for doing hair,” he said. “They’d bully me, calling me gay, and make me feel bad about not being a mechanic like my dad or a football player like my brother.”

Katie Katon owns the Leicester salon where Mr. Appleton began his career as a teenager and worked for a decade. Over that time, they had a romantic relationship and two children, a son, now 17, and a 15-year-old daughter. But at 26, Mr. Appleton came out as gay. It was a period both he and Ms. Katon describe as “dark.”

“Hiding who you are for so many years causes a lot of pain inside, wouldn’t it?” she said. “The way Chris dealt with that pain was trying to be the best he could be in other areas.”

He eventually left Leicester for London in 2016, which is when he picked up his first big-name client, Rita Ora.

“I’d win these hairstyling competitions, or I’d get an important magazine cover,” he said. “There are these moments, and you’d think, ‘This is going to change my whole life.’ But they never do. All they ever are are springboards to the next thing. I don’t think I’ve had any moments that have been, like, ‘Oh! I’ve made it.’”

Mr. Appleton, who now lives in Los Angeles, and Ms. Katon are constantly in touch about his work, trading styling ideas. (She weighed in on the J. Lo looks.) And she still calms him through the inevitable panic of a big gig.

“At the Super Bowl, it wasn’t until he was in a golf buggy on his way to the field and could hear the crowd that he realized how massive it was,” she said. “When he got back to the hotel that night, he was stressed about the hair. I said, ‘Chris, take some time and go online — everyone’s going mad.’”

This year Mr. Appleton is introducing a YouTube channel, mostly for his fans who crave hair tutorials and an insider-y look at his work life. “It’s weird to think about it all,” he said, pensive at considering his life and work.

But he is almost immediately snapped out of it by the arrival of a text. It’s from Ms. Kardashian West, wanting to kick around hair ideas for the next thing. It’s early February, and the Met Gala is, after all, just three months away.