When Qu Tongzhou, a photography assistant in Shanghai, set out on a long-awaited trip to western China in June, she found the cities she visited to be unwelcoming. As an aftereffect of the country’s “zero-Covid” policies, locals were leery of travelers, and some hotels refused Ms. Qu, fearing she could introduce the virus.

So Ms. Qu turned to Tantan and Jimu, two popular Chinese dating apps with Tinder-like features. She was aware of the risks involved in meeting strangers, but the apps yielded a wellspring of new friends, including a biotech entrepreneur in the city of Lanzhou, a Tibetan doctor in the town of Xining, and a public official in Karamay, a northwest city of Xinjiang. At each stop, her matches provided lodging and took her to bars and other local spots.

“If I didn’t use these apps, I wouldn’t have met many people,” Ms. Qu, 28, said. “No one would have taken me out on the town.”

Over the past two years, China has cracked down on much of its domestic technology industry, banning for-profit online tutoring agencies, restricting video games and slapping multi-billion-dollar antitrust fines on the largest online shopping platforms. Some of China’s once-vaunted tech titans, like Jack Ma, the founder of the e-commerce firm Alibaba, have stepped back from public view.

But one corner of China’s technology industry has flourished: dating apps.

The number of dating apps in China with over 1,000 downloads soared to 275 this year from 81 in 2017, according to data.ai, an analytics firm. Downloads of the apps have increased, as have in-app purchases.

Investors have also poured more than $5.3 billion into dating and social networking companies in the country last year, up from $300 million in 2019, according to PitchBook. And China’s largest tech companies, such as ByteDance and Tencent, are testing, acquiring and investing in new apps that promise to bring strangers together.

These apps are flourishing — and Beijing appears to be leaving them alone — for more than just romantic reasons. They promise to nudge people toward marriage at a time when China’s marriage and fertility rates are at record lows, but the apps also are helping users combat loneliness as Covid lockdowns have wreaked havoc on social connections.

For many people, the apps have become virtual sanctuaries — a 21st-century twist on what urbanists called the “third place,” a community between work and the home — to explore hobbies, discuss popular topics and meet new friends.

“It’s really difficult to meet people offline,” said Raphael Zhao, 25, a recent college graduate in Beijing. Mr. Zhao downloaded Tantan in April after being locked down on his campus over zero-Covid measures. “Because the pool is so large on these platforms, it gives you this hope that you’ll meet someone that you live with.”

Chinese authorities have taken action against dating apps in the past. In 2019, Tantan and another dating app called Momo suspended some in-app features after regulators dinged them for neglecting the spread of pornographic content on their platforms.

But unlike online tutoring and cryptocurrency trading, areas that China’s regulators have unambiguously quashed, dating and other services centered on social encounters have remained relatively unscathed as the apps have explicitly framed their goals as helping Chinese society to thrive.

Zhang Lu, the founder of Soul, a dating app backed by Tencent, has said that “loneliness is the core problem we want to solve.” Blued, the most popular gay dating app, bills itself as a public health and H.I.V.-awareness app. Its site highlights its work on H.I.V. prevention, collaborations with local governments, and its founder’s encounters with high-ranking officials such as Premier Li Keqiang. (Blued’s founder stepped down last month, alluding to the challenges of running a L.G.B.T.Q. app in China, but the app’s downloads have remained constant.)

“Rather than simply cracking down, dating apps are seen as technologies that can be effectively co-opted by the state,” said Yun Zhou, an assistant professor of sociology and Chinese Studies at the University of Michigan.

When internet dating arrived in China in the early 2000s, the power to form relationships — once disproportionately in the hands of village matchmakers, parents and factory bosses — increasingly fell onto the individual. Many were eager for the shift, gravitating to features on WeChat, the popular messaging app, which enabled chatting with strangers.

The trend accelerated in the 2010s with the arrival of dating apps like Momo and Tantan, which emulated Tinder. Alongside Soul, they became China’s three most popular dating apps, amassing over 150 million monthly active users in total.

Soul and Momo declined to comment. Tantan, which is owned by Momo, did not respond to a request for comment.

The apps themselves have changed. Tantan and Momo had long matched users based on their physical appearance, leading to accusations that the platforms cultivated a hookup culture. More recently, these apps have started using people’s interests, hobbies and personalities as the basis for new social encounters.

Douyin, which is owned by ByteDance and is China’s version of TikTok, and Little Red Book, an app with similarities to Instagram, have built “social discovery” features that use their knowledge of people’s preferences to match them. Soul has become especially popular in the past few years for its avatar profiles and its practice of linking users based on personality tests. Last year, the app surpassed Tantan and Momo as the most downloaded dating app on the Chinese iOS store.

“What I like most about Soul is that it doesn’t force you to look at a photo and swipe left and right,” said Yang Zhongluo, 23, a masters student in Beijing who met some of her close friends on the platform. “It lets you post, share ideas and then everyone can like and comment.”

In July, Soul filed for an initial public offering in Hong Kong after tripling its monthly active users to 31 million between 2019 and 2021. Three-quarters of its users were born between 1990 and 2009, according to its prospectus. (It filed to go public in the United States in 2021, but stepped back from such an offering.)

Many users of these dating apps appear less interested in romance than in meeting friends. In an October survey conducted by a Chinese research institute, 89 percent of respondents said they had used a dating app before, with a majority saying they wanted primarily to expand their social circles, not find a partner.

Vladimir Peters, a Shanghai-based developer who is working on his own dating app, said many younger Chinese now want the apps to provide a more holistic experience that blends entertainment and hobby exploration — not just a love match.

“Young Chinese like gimmicks such as icebreakers and other playful things that are the starting points for communication,” he said.

Many of the biggest Chinese tech companies that make social networking and dating apps appear to have reached the same conclusion. Tencent, the owner of WeChat, has released 10 apps in the social networking and dating category in the past few years. It is developing a virtual party game in which users can simulate the experience of social gatherings without going to one.

NetEase, a gaming company, has also built a dating app that recommends matches based on people’s shared interests. In March, ByteDance, the owner of TikTok, acquired PoliQ, a start-up that uses virtual reality to enhance social networking.

During the Shanghai lockdowns in April, Ms. Qu, who had long prized offline encounters and physical facial features on dating apps, said she began to cherish her matches more as digital companions.

“We began to connect with each other purely on a psychological level,” she said. “We were just grateful for each other’s company.”