What I found on these sites was more pitiful than fear-inspiring. Sure, some alt-tech platforms were filled with upsetting examples of Nazi imagery and bigoted garbage. But most were ghost towns, with few active users and no obvious supervision. As technology products, many are second- or third-rate, with long load times, broken links and frequent error messages. A few had been taken offline altogether.

Recently, I spent several days testing a number of these alt-tech services. I created accounts, explored their features and interfaces, and interviewed users of each site about their experiences. (With my wife's permission, I even created a WASP.love profile and advertised myself as a New York journalist looking to interview lovelorn white supremacists. Oddly, I got no takers.)

More than a dozen "alt-tech" companies have now emerged, each promising a refuge from political correctness and censorship. There is Gab, a kind of alt-Twitter social network that began last year, whose early adopters included prominent figures like Milo Yiannopoulos and Andrew Anglin, the founder of the neo-Nazi Daily Stormer website. There is WrongThink (alt-Facebook), PewTube (alt-YouTube), Voat (alt-Reddit), Infogalactic (alt-Wikipedia) and GoyFundMe (alt-Kickstarter). There is even WASP.love, a dating site for white nationalists and others "wishing to preserve their heritage."

In recent months, as sites like YouTube, Twitter and Facebook have cracked down on hate speech and barred several high-profile conservative users, the alt-right made a declaration of technological independence from Silicon Valley. Hard-right activists vowed to create their own versions of these digital services, on which all views would be welcome, no matter how crude or incendiary.

If you've lost sleep worrying about the growing power of the alt-right — that shadowy coalition that includes white nationalists, anti-feminists, far-right reactionaries and meme-sharing trolls — I may have found a cure for your anxiety.

If the alt-right's ideology harks back to 1940s Germany, its web design might transport you to 1990s GeoCities. Even the movement's own adherents have grown frustrated. One Gab user, who claimed to be using the site while temporarily suspended from Twitter, complained in a public post about the site's technical inferiority.

"I'm an investor in Gab," wrote the user, who goes by the username @AnewThomasPaine. "I believe in the idea, but I'm disappointed in the platform." In another message, he wrote: "I barely use it as there are few active users, and few essential features even after a year."

Gab, which claims to have more than 300,000 registered users, was supposed to be an alt-tech success story. The service attracted reams of attention when it launched last year, and it raised more than $1 million in a crowdfunding campaign, making it the rare alt-tech platform with significant resources. Utsav Sanduja, Gab's chief operating officer, told Slate this year that the company was starting an organization called the "Free Speech Tech Alliance," and had recruited more than 100 Silicon Valley engineers to help.

But today, Gab is buggy and confusing, and much of the activity on the site appears to come from a small core of frequent users. Several of the well-known figures who once posted on the site have abandoned it. ("I'm a creature of habit, and fell out of habit of posting there," Mike Cernovich, a notorious right-wing media personality, told me.) The site also had its own censorship drama earlier this year, after moderators removed a post that mocked Heather Heyer, the activist killed during the Charlottesville protests.

Gab's founder, Andrew Torba, declined to comment on the site's progress, telling me in a Gab message that "I don't do interviews with fake news outlets."

Instead, I spoke with Cody Wilson, a developer in Texas who is behind another alt-tech service. Mr. Wilson's product, a crowdfunding site called Hatreon, was meant to give alt-right personalities and others a way to raise money for projects deemed too risqué for mainstream crowdfunding platforms such as Patreon and Kickstarter.

Hatreon got off to a fast start, with more than 400 creators raising about $25,000 per month on the platform. But lately, it has fallen into disrepair. According to Mr. Wilson, a major credit card company, which he declined to name, kicked Hatreon off its network last month, preventing many users from funding projects on the site and all but killing the company's prospects for growth. Today, visitors to Hatreon are greeted by a message saying that "pledging is currently disabled while we upgrade our systems."

Mr. Wilson, who does not describe himself as alt-right, said he has accepted that building a viable alt-tech business might be impossible, given the practical constraints.

"I don't understand how any of them plan to be profitable," he said.

Things aren't going much better for WrongThink, which went online in late 2016 with aspirations of becoming a free-speech alternative to Facebook and Twitter. A year later, WrongThink has only about 7,000 registered members, according to the site's founder, who goes by the username Bane Biddix.

Far-right activists have been trying to build alternative tech platforms for years, with little success. A decade ago, white nationalist websites with names like New Saxon and PodBlanc sprang up to compete with Myspace, Friendster, and the other social giants of the era. But most of those sites fizzled when their creators ran out of money or got into legal trouble. And none came close to reaching a large mainstream audience.

Granted, it is still the early days for this new wave of services, which are coming of age during the Trump years and could benefit from changing norms around P.C. culture and acceptable speech. Some alt-right leaders are hopeful that a coming "purge" on Twitter — their phrase for a change in the site's hate speech policies, which Twitter plans to enforce beginning next week — will send scores of disgruntled users scurrying to alt-tech platforms.

But Mark Pitcavage, who studies right-wing extremism at the Anti-Defamation League, told me that alt-tech companies face several structural barriers. Not only do they have to build a compelling product and attract users — a steep challenge even in the best of circumstances — but they must do it without access to mainstream funding sources, such as venture capital firms and angel investors, which provide much of the fuel for other tech start-ups. They also rely on finding companies that are willing to host their services and process their payments.

"Being on the internet is a group venture," Mr. Pitcavage said. "You rely on an internet service provider, a domain name service, a credit card processor. It's a very common thing for one or more of these entities not to want to do business with a white supremacist group."

There is also a talent shortage among alt-tech companies, many of which rely on activist volunteers, and few of which can afford to pay the kinds of salaries demanded by top-tier programmers.

"Speaking frankly, you're not getting 10x engineer talent with these people," said Mr. Wilson of Hatreon, using a popular Silicon Valley term for a star employee. "No one's lining up for this."

Alt-tech is also a victim of the same market forces that have held back other small tech start-ups. Much of the internet's basic architecture is controlled by a handful of gatekeepers — Facebook, Google, Apple and Amazon among them. Those companies run back-end services that allow developers to build reliable products, the app stores that allow them to reach a mass audience, and the advertising platforms that allow them to make money. Without the support of Silicon Valley's giants, it's nearly impossible to compete, no matter what your political views are.

"If someone with sufficient money and determination magically materialized, I'm not saying it's impossible, but even then it wouldn't be easy," Mr. Pitcavage said.

The good news for the alt-right's detractors, then, is that the movement's vision of a flourishing parallel internet seems doomed to fail.

The bad news is that, without a functional alternate ecosystem, it may be harder to quarantine the views of neo-Nazis and other noxious ideologues to little-used corners of the internet, far from the vast majority of users. Facebook, Twitter, and other mainstream services will continue to be the dominant venue for ideological battles, and keeping these platforms free of hate and misinformation will remain those companies' responsibility. Let's hope they're up to the challenge.

Email Kevin Roose at kevin.roose@nytimes.com, or follow him on Facebook at facebook.com/kevinroose and on Twitter @kevinroose.