A federal appeals court on Friday blocked Utah from enforcing a law that would have required social media companies to verify the age of every user in the state and to obtain a parent’s consent before anyone under 18 could open an account.

In a 2-to-1 decision, a panel of the United States Court of Appeals for the 10th Circuit held that the law, which was to take effect in January, imposed a “content-neutral but speech-burdening” requirement on adults, who would have had to hand over identification to speak on the largest platforms. The court said the state had not shown that less intrusive measures, such as device-level parental controls, would fail to protect minors.

The ruling deepens a split among the federal circuits. The Fifth Circuit upheld a similar Texas statute in 2025, and the Ninth Circuit struck down most of a California measure in the spring. Lawyers on both sides said Friday that the disagreement made Supreme Court review likely, possibly in the term beginning next October.

“The question is no longer whether states can protect children online,” said Rachel Ostrowski, a professor of constitutional law at the University of Utah who was not involved in the case. “It is whether they can do it by asking 2.5 million adults for their driver’s license first.”

The challenge was brought by a trade association representing the major platforms and by three Utah residents, including Ethan Blackhurst, a 19-year-old college student from Provo who argued that he would have been locked out of accounts he used for a part-time photography business during the months before his 18th birthday. “I built my whole client list on there,” Mr. Blackhurst said after the ruling. “The law treated me like a problem to be managed.”

The state argued that the law was a public health measure comparable to minimum ages for alcohol and tobacco. It cited data from the Utah Department of Health and Human Services showing that emergency room visits for self-harm among 13- to 17-year-olds rose 41 percent between 2015 and 2024.

The dissenting judge agreed with the state, writing that the majority had “elevated the convenience of adults over the documented injuries of children,” and noting that the law allowed verification through a third party that would not retain identity documents.

The decision does not affect a separate Utah provision, which took effect in 2025 and has not been challenged, that requires platforms to disable autoplay and infinite scrolling features for users they know to be minors.

Supporters of age-verification laws, who have won passage in 14 states, said they would press on. Parents’ groups gathered on the steps of the State Capitol in Salt Lake City on Friday evening, where Carla Jensen, who organized the rally, said her 15-year-old daughter had spent an average of seven hours a day on one app before the family removed it. “Every month this gets delayed is a month those companies get for free,” she said.