Flipping channels during TV’s after-hours used to have a familiar coziness: Joke-filled monologues with toothless political barbs, followed by a sketch, followed by interviews in which guests hawked their latest projects. But that’s old school.

Today, amid fierce competition for eyeballs and viral video segments, late-night broadcast hosts and their cable brethren, most of whom pack a guest-free half-hour once a week with headlines and humor, have been using authenticity and deeply personal stories to turn their shows into must-see television.

It could be Seth Meyers recounting the birth of his son in his apartment building’s lobby on “Late Night,” Jimmy Fallon paying tribute to his late mother on “The Tonight Show” or Jimmy Kimmel discussing his newborn son’s surgeries through tears as he pleads for universal health care on “Jimmy Kimmel Live!” Simultaneously, most have also brought their own political POVs into play when talking about the day’s headlines: Stephen Colbert’s “The Late Show” takes nightly, sustained digs at the Trump administration, and even cheerful raconteur James Corden devotes sketches and part of his “Late Late Show” nightly monologue to politics, including a heartfelt speech to the victims of the Ariana Grande concert bombing in Manchester in 2017.

“People are spending time with us that they would normally only spend with friends and family, and there’s an intimacy that’s nice,” says Meyers. “When I started on ‘Late Night,’ the audience wanted to see a late night show. Now, they want to see my late night show.”

Meyers isn’t alone in feeling some kind of ownership over his wedge of the TV schedule. The degree to which a host fills his or her time with political humor or personal experiences and insights has been shown to win them the loyalty of nightly viewers. Audience engagement is the name of the game, and it all comes down to how much of his or herself the host is willing to put into his or her show.

“What you’re seeing is authenticity being rewarded, no matter who the host is,” says “Late Show” showrunner Chris Licht. “Audiences are genuinely responding to authenticity, and there are some great people in late night. The most successful ones are the ones who are being true to themselves.”

It doesn’t always come easy: While Colbert and Meyers (and Kimmel, to some extent) have continued to keep a lot of their content focused on headlines; Corden and Fallon hew closer to a traditional nightly variety show.

“When I took this job on, I had never considered that we’d be talking about horrific mass shootings or terrible events,” says Corden. “We talk about politics every single night. The biggest thing is we don’t want to only do that.”

Adds Fallon: “Sometimes, I don’t know how to perform when there’s extremely tough things going on in my life. My mom passing away was one of the worst things that ever happened to me, but the show must go on, and I have to do my job.”

“These folks are acting as social commentators, but they’re acting in a personal way,” says Tammy Vigil, associate professor of communication studies at Boston U. “Audiences are drawn to it because it helps them make sense of the world, [make it] a little more manageable, and maybe a little less — if not scary, less troubling.”

Opening up can have its rewards. Trevor Noah won his first Emmy in 2017 for his “The Daily Show: Behind the Scenes” web segments, which capture off-the-cuff events going on during the commercial breaks, and he occasionally includes his own personal experiences — like being pulled over by police multiple times — to put a personal spin on real-life conflicts.

“As a stand-up comedian, I’m constantly sharing with my audience,” he says. “We have a limited amount of time on air, so I’ve been forced to find limited ways to connect with the audience.”

Meanwhile, “Watch What Happens Live!’s” Andy Cohen is an open book outside his show — with a 24-hour radio channel and multiple bestselling diaries of his life — but on the show he limits both personal and political discussion. Instead, he engages by being able to include live call-ins from audience members.

“They literally are part of the conversation,” he explains, adding that by taking the show on the road, they keep things fresh in additional ways. “I’m here to make you smile at the end of a rough day. … I’m hosting a live cocktail party every night.”

Still, it’s a tightrope every host walks, every time they tape a show: While they all have large writing staffs, much of the decision about what to talk about and what to leave out is made on the fly.

“Every monologue is a reflection of Stephen’s personal take,” says Licht. “We don’t generally spend a lot of time deciding what is strategically a good thing for him to talk about. It goes the other way, which is part of why he’s resonating with viewers.”

Still, a good segment that goes viral is holy grail for late night, whether it’s a heartfelt eulogy or a wicked stab at Washington, D.C.

“If you make something good, it will travel and people will see it,” says Corden, who last year managed to parlay his show’s “Carpool Karaoke” bit into a spinoff series and prime-time specials.

For now, there’s clearly an abundance of content to choose from, thanks in great part to the headline-maker-in-chief. But if these shows were all political talk all of the time, there would be “potential risk for fatigue,” Vigil says.

She finds the political talk “too much” sometimes and has “to tune out for a while.”

Meyers himself admits he wouldn’t mind a bit of a break from the news torrent: “We’re looking forward to changing topics,” he says. “It will be a challenge, but people quit smoking and it’s not easy — but they feel great when they do. I’ll wear a patch for the first few shows.”

Licht, on the other hand, has resigned himself to the fact that this is “the new normal” and insists it is sustainable.

“We are built to handle what people are talking about as quickly as possible — our team is built to mine whatever’s in the public discussion,” he says.

“You can’t ignore the news cycle now,” says “Full Frontal” host Samantha Bee. “If you ignore it, you do so at your peril. That is all anyone cares about. And we should care — deeply.”

It’s just a matter of how the news is presented that determines success for late night shows.