You won’t find Red Pill News or the X22 Report on YouTube anymore. The far-right online shows were taken down in the fall of 2020 after the major social media and tech companies started purging accounts that spread the QAnon conspiracy theory.

But you will find both of them on a video-sharing platform called Rumble, where their content ranks among the most popular on the site.

Over the last week, as Republicans opened a misleading attack on Judge Ketanji Brown Jackson as too lenient with criminals who sexually abuse children, Red Pill News and the X22 Report posted videos claiming that her nomination to the Supreme Court by President Biden was all the proof anyone needed that a cabal of pedophiles operated at the highest levels of the government, a belief QAnon adherents hold.

“Think about the bigger picture,” the host of the X22 Report, which has more than half a million Rumble subscribers, implored his viewers in an episode posted on Wednesday. “Right now, people are being taught about pedophilia. People are listening to this, and they’re seeing exactly how these people think and how they’re trying to normalize it.”

In one day, that episode was viewed almost 220,000 times on Rumble, which has experienced explosive growth since conservatives and supporters of former President Donald J. Trump embraced it after the 2020 election. Its users and financial backers see it as the new frontier in social media — a network built by and for them, where virtually anything goes.

Rumble’s chief executive pitches the company, which is based in Toronto, as “immune from cancel culture.” It has tens of millions of dollars in financing from right-of-center entrepreneurs like the billionaire Peter Thiel, and Mr. Trump entered into an arrangement for Rumble to provide his new social media service, Truth Social, with the technology and operational support that it lacked itself.

Once better known for viral videos of cats and toddlers, Rumble now draws 44 million monthly visitors, according to the analytics firm Similarweb, giving it a larger reach than other top destinations for conservative content, including Breitbart, Newsmax and The Daily Wire. In the first nine months of last year, the most recently available financial information, Rumble generated more than $6.5 million in revenue, most of it from advertising, but was not profitable. It has announced plans to trade publicly, as soon as the middle of this year, after merging with a special purpose acquisition company.

The story of Rumble’s success is instructive for both sides of the tense debate over balancing the right to free speech with the growing threat that disinformation poses to the stability of governments around the globe. For those who argue that Google and Facebook algorithms are blunt, deeply flawed instruments for policing discourse, Rumble offers a welcome alternative, albeit an imperfect one. And for those who fear that lawmakers and technology companies aren’t doing enough to tame false and fabricated information ahead of the next presidential election, Rumble has opened up a potentially dangerous loophole.

“There is something very significant about Rumble that I don’t think people appreciate,” said Angelo Carusone, president of Media Matters, the liberal media watchdog. Mr. Carusone said the painstaking work that went into persuading Facebook, Google and Twitter to be more aggressive about policing fake and inciting content prevented a lot of it from breaking through to a wider audience.

“Rumble basically changes that game,” he added.

Rumble’s chief executive, Chris Pavlovski, has said he did not set out to create a platform where right-wing content is favored when he started it in 2013. Rather, he said, he envisioned Rumble as an alternative to the approach that Google and other large tech companies took a decade ago when they began to promote the content of a select group of influencers over everyday users.

“There is no ideology here. If anything, we’re just neutral,” Mr. Pavlovski said in an interview last month with a popular Rumble content creator.

He has described his mission in lofty, virtuous terms. “We are a movement that does not stifle, censor or punish creativity,” he said in announcing Rumble’s plans to go public. More recently, he has chastised social media and search engine companies like DuckDuckGo, a Google alternative popular on the right that angered some users when it said it would steer people away from sites that promoted misinformation about Russia’s invasion of Ukraine. Mr. Pavlovski announced on Twitter that he had deleted its app from his phone.

But Rumble’s democratizing vision for speech online has so far mostly appealed to people on the right. That includes numerous extremists who use their Rumble accounts to deny the effectiveness of vaccines, play down the horrific human toll of Russia’s aggression in Ukraine and question the legitimacy of the 2020 election. Still, criticism of the often capricious and inconsistent nature of online censorship rings true beyond those with fringe beliefs.

There is a large audience to be had, and one that some who study far-right content online warn has been left unchecked to grow into a powerful political weapon for conservatives and supporters of Mr. Trump.

“It’s already succeeded — this alternate universe has already bloomed,” said Denver Riggleman, a former Republican congressman and an intelligence analyst who is working with the commission in Congress investigating the Jan. 6 attack on the Capitol.

Mr. Pavlovski and Rumble representatives did not respond to interview requests.

But he has made clear in streamed remarks to Rumble creators and to others that his ambitions are far greater than increasing traffic to his website and app. With investments from like-minded critics of Big Tech like Mr. Thiel, Mr. Pavlovski has described a vision for building a “new internet” — a kind of alt-web that is entirely distinct from the dominant players in the industry.

Rumble has already built out its own cloud service infrastructure and video streaming capacity, offering it and its partners greater independence from the Amazons and Microsofts of the internet — and the assurance that they can’t be shut down if one of those providers decides to pull the plug over objectionable content. Looming large in the minds of Rumble fans is the experience of the social media network Parler, which effectively shut down once Amazon said it would no longer host the site on its computing services after the Jan. 6 attacks last year.

The promise of independence from the tech giants led Mr. Trump to have Rumble provide technology and cloud services for Truth Social, which has struggled to become fully operational on its own. In a statement announcing the partnership in December, Mr. Trump said he had picked Rumble because it’s among the service providers “who do not discriminate against political ideology.”

Rumble has also secured exclusive arrangements with popular content creators who have a following beyond conservatives and Trump supporters, such as the journalist Glenn Greenwald, who has been vocal about his beliefs that technology behemoths and the mainstream media have too much power to quash speech. Rumble highlighted its partnership with Mr. Greenwald as an example of its content-neutral approach. (As for what it considers out of bounds, Rumble says it does not tolerate anything that is overtly racist, promotes violence or breaks the law.)

But there are also the popular Rumble creators the company doesn’t talk about in news releases, like Alex Jones of Infowars, who was barred from YouTube and other mainstream platforms in 2018 and now has more than 100,000 Rumble followers.

That’s a small number compared with the millions on YouTube who followed Mr. Jones, who has spread bogus theories that the 2012 Sandy Hook massacre was staged as part of a government plot to confiscate firearms. Those who study the right-wing media ecosystem say it is difficult to tell how large the overall audience for hard-right content is, in large part because the traffic data available for individual sites includes a lot of overlap from users who frequent more than one.

“It’s an intensely engaged population,” said Yochai Benkler, a professor at Harvard Law School who is a co-author of a book about the ways conservative outlets reinforce their messages through repetition and shut down dissent. For an individual platform like Rumble, he added, the audience is likely to be larger than whatever the size is on paper.

“All of my skepticism of how many people there are bumps up against the reality that 80 million people voted for Trump,” he said. “Fox doesn’t have 80 million viewers. So there’s something going on.”

One of Rumble’s marquee names is Dan Bongino, the pro-Trump host and former Secret Service agent who replaced Rush Limbaugh in some radio markets and streams his daily show on Rumble to 2.2 million subscribers. Mr. Bongino’s path to Rumble illustrates the inherent difficulties of policing misinformation and conspiracy theories. YouTube started cracking down on him in the fall of 2020 for violating its policies meant to stop the spread of false stories about the coronavirus.

After YouTube prevented Mr. Bongino from collecting ad revenue from the site, he announced that he was taking an equity stake in Rumble and made it his preferred video platform. “We need a home,” he said at the time. “We need somewhere to go where conservative views won’t be discriminated against.”

In the weeks and months that followed, as Mr. Trump refused to accept his loss in the election and YouTube blocked content that bolstered his false claims of widespread voter fraud, others jumped on board with Rumble, too, including One America News.

On the day after Rumble announced its OAN partnership, Mr. Pavlovski insisted that his company would never censor that kind of political speech. “Rumble will not adopt a policy like this,” he said, citing an unimpeachable inspiration for his resolve: Galileo, who was charged with heresy by the Roman Catholic Church for theorizing that the Earth revolved around the sun.