The fate of TikTok — and its 170 million American users — hangs in the balance, as the Supreme Court considers the constitutionality of a law that would ban the platform in the country if its China-based owner, ByteDance, doesn’t sell off its U.S. operation by Jan. 19.

If the court upholds the law — as a lower court did last month — TikTok’s days in the country would be numbered.

“On January 19th, as I understand it, we shut down,” TikTok lawyer Noel Francisco told justices during oral arguments on Friday.

That doesn’t mean the viral video app will automatically disappear from peoples’ phones, or that individuals will risk punishment just for logging in.

But it will get harder for the platform’s users in the U.S. to access the app, says Kate Ruane, director of the Free Expression Project at the Center for Democracy and Technology (which joined an amicus brief supporting TikTok and its users’ protected speech).

“I think the biggest obvious result of this law going into effect is that … it’s going to require more technical savvy to access TikTok,” Ruane told NPR. “And that in and of itself is going to be too big of a barrier for lots and lots of people to continue to access TikTok, or to continue to try to use TikTok as a service.”

TikTok officials say it is possible that on Jan. 19, when U.S. users try to open the app, a prompt will show up indicating the service is no longer available in the country. This is what happens when someone tries to launch TikTok in India, which banned the app in 2020. 

It’s also possible users will be able to access the app but it may be buggy, operate slowly or crash often, the TikTok official said.

Here’s what could happen and how to prepare.

Fine print: How the law would actually work 

The Protecting Americans From Foreign Adversary Controlled Applications Act (PAFACA), which President Biden signed into law in April 2024,, grants the government the authority to ban foreign-owned apps that it deems a threat to national security.

The bill passed with considerable bipartisan support, as many lawmakers worry that the Chinese government could access Americans’ data — through TikTok’s parent company — and use it to surveil them, spread misinformation and sway public opinion.

While the law concerns TikTok, it actually targets the companies that make the platform accessible in the U.S., including app stores like Apple’s App Store and Google Play, and cloud service providers like Oracle.

The fine print makes it illegal for any such entities to “distribute, maintain, or update (or enable the distribution, maintenance, or updating of) a foreign adversary controlled application” either through a marketplace or internet hosting services.

In mid-December, Democrats on a House committee dealing with competition between the U.S. and China sent letters to the CEOs of Apple and Google warning the companies to take steps to ensure they can “fully comply with this requirement” by the deadline — which would have an immediate impact on users.

“If you already have [TikTok] on your phone, it’s not going to disappear from your phone on January 19th or January 20th,” Ruane says. “It will, however, very likely disappear from application stores.”

That means users will no longer be able to download the app or any updated versions of it.

And without the ability to update, the platform won’t be able to fix bugs, add features or address security concerns. Eventually, Ruane says, it may also become incompatible with the operating system of certain phones.

“Over time … the service that you get with the application will be worse and worse and worse,” she adds, though it’s too soon to tell whether that will be a matter of days, weeks or months.

Action items: Preparations and potential workarounds for TikTok users 

As Jan. 19 and the potential TikTok ban approach, experts like Ruane recommend that users download their data and save any videos that they want to be able to access in the future.

“The other thing is to remember that even after this law takes effect, if it does, it will not be illegal for them to continue to use TikTok if they have it on their phones already — or even if they manage to acquire it from some other source than an app store,” she says. “This law will not apply to individual people accessing TikTok.”

One of the most-discussed workarounds is something called a virtual private network, or VPN, which encrypts users’ location data and makes it look like they are accessing content from another country.

They are commonly used in countries with strict internet restrictions to access blocked social media platforms, streaming services and other geographically limited content.

“Even as the application degrades on your phone, you may still be able to access it through a virtual private network on a web browser,” Ruane says.

There are also ways to download TikTok outside the Google and Apple app stores, through processes respectively known as “sideloading” and “jailbreaking.”

But they’re not without potential complications or consequences: Apple, for example, won’t honor warranties for jailbroken iPhones. Ruane thinks the extra steps will deter many TikTok users.

“It is a barrier to accessing the application and it is also something that you would have to weigh, like ‘Is it really worth it to me to access TikTok, to do all of this or learn how to do all of these required technical things?’” she says. “And I think for a fair number of users who are just casually using the application, the answer will probably be no.”

Uncertainties: How the Trump administration could fight a ban  

It’s no coincidence that the potential ban would take effect on Jan. 19, the last full day of Biden’s term. That puts the ball in the court of President-elect Donald Trump, who has his own strong views on TikTok.

While Trump previously disparaged the app as a national security threat and even tried to ban it during his first term, he has since become a staunch defender of the platform and even asked the Supreme Court last month to pause the start date of the law in question.

As Ruane sees it, Trump has three choices for how to proceed once in office, and all of them are complicated.

For one, he could try to convince Congress to repeal the original 2024 law that requires ByteDance to divest TikTok, which both the House and Senate passed with overwhelming support.

“That’s pretty straightforward, but it’s also politically incredibly difficult to do because it would require the changing of votes for many, many, many members of Congress,” Ruane says.

Trump’s second option is to direct the Justice Department and attorney general to not enforce the law, essentially giving Google, Apple and others the option to continue providing services to TikTok.

But Ruane says that’s also easier said than done, as lawyers within those companies would still see — and likely seek to avoid — “gigantic legal risk” in flouting the law, which includes hefty penalties.

“So if anybody uses your service to access TikTok and you are in violation of the law, it’s $5,000 per person that does that,” Ruane says. “If you were to take the president up on his offer and continue to provide services to TikTok, even though you’re technically in violation of the law, that’s $5,000 times hundreds of millions of people.”

The third potential option has been posited by Alan Rozenshtein, an associate law professor at the University of Minnesota Law School and research director at Lawfare. As he told NPR’s Fresh Air in December, Trump could “just declare that the law no longer applies.”

Trump could choose to use his broad authority under the statute to determine that ByteDance has engaged in a “qualified divestiture” of TikTok after all, as long as it has taken certain steps to that effect.

“There’s a scenario in which ByteDance could move some papers around, shift some assets from one corporation to another corporation, do some fancy legal work, and that would give Trump enough, basically, cover to declare that TikTok is no longer controlled by ByteDance,” Rozenshtein said.

That’s not an airtight approach either, Ruane says, since it could be challenged in court either by competitors or the entities involved.

One option under discussion among TikTok stakeholders is bringing back a national security agreement known as Project Texas, which involves tapping Austin-based Oracle to host all U.S. user data. Oracle would also oversee all data flows between TikTok’s U.S. operation and Beijing. The plan would also allow the federal government to invoke a “kill switch” that would shut down TikTok if terms of the agreement were violated.

The deal initially had support in the Biden administration, but talks stalled. People close to talks about TikTok’s future say it is possible Trump brings Project Texas back, with Trump potentially determining that the agreement makes TikTok in compliance with the divest-or-ban law.

At the end of the day, Ruane says it’s unclear what, if anything, Trump may do to try to bring back TikTok — an app she says is “not immediately replaceable,” even as new and existing platforms are sure to vie for its many displaced users.

NPR’s Bobby Allyn contributed reporting.