How soon could US ban TikTok after Congress approved bill?

The video sharing app has millions of users around the world, but faces growing questions over the security of users' data and its links to the government in Beijing.

The House of Representatives and Senate have now both passed legislation which, among other things, forces the platform's parent company to divest.

President Joe Biden has vowed to sign the ban into law.

Who wants to ban TikTok in the US and why?

Lawmakers from both major US parties have pressed for a law that bans TikTok unless ByteDance agrees to sell the app to a non-Chinese company.

They fear the Chinese government could force ByteDance to hand over data about TikTok's 170 million US users. TikTok insists it would not provide foreign user data to the Chinese government.

On 21 April, House lawmakers approved a $95bn (£76bn) foreign aid bill with funds for Ukraine, Israel and Taiwan that also clears the way for the forced sale of TikTok.

On 23 April, the legislation passed the Senate, and will now be sent to Mr Biden to be signed into law.

This is not the first time American authorities have struck out at TikTok.

Former US President Donald Trump tried to ban the app when he was in the White House in 2020.

But Mr Trump - now confirmed as the Republican candidate for the 2024 presidential election - has criticised the new legislation, arguing that limiting TikTok would unfairly benefit Facebook.

• Is TikTok really a danger to the West?
• Can TikTok's owner afford to lose its killer app?

When could a TikTok ban happen?

Even after Mr Biden signs the bill, the ban won't take effect immediately.

In fact, it would likely take several years before Americans are unable to access the app, as ByteDance sues - likely all the way to the Supreme Court - to block the forced sale.

Also, the legislation gives ByteDance nine months to sell TikTok to an American buyer, with an additional three-month grace period, before any ban would take effect.

That means that the sale deadline would most likely come some time in 2025, after the winner of the 2024 presidential election takes office. If Mr Trump wins, he may seek to block the ban from being implemented.

How would a TikTok ban work?

The most straightforward way for the US to ban TikTok would be to remove it from app stores, such as those operated by Apple and Google for iOS and Android devices.

App stores are how most people download apps on to their smartphones and tablets, so the ban would stop new users from getting TikTok.

That means people who already had the app would no longer be able to get future updates designed to improve security or fix bugs.The US bill forbids applications controlled by US adversary countries from being updated and maintained in the US.

It gives broad powers to the president to limit apps with ties to Russia, China, Iran and North Korea.

What has TikTok said it will do about the legislation?

TikTok has been highly critical of the legislation, calling it an affront to the US right to free speech.

Chief executive Shou Zi Chew warned the bill would give "more power to a handful of other social media companies", and put thousands of American jobs at risk.

ByteDance would have to seek approval from Chinese officials to sell TikTok, but Beijing has vowed to oppose such a move.

How have TikTok users in the US responded?

Some US creators and users have also criticised the proposed ban.

Tiffany Yu, a young disability advocate from Los Angeles, told the BBC at a protest outside the White House the platform was vital to her work.

TikTok asked its 170 million US users to contact their political representatives and ask them not to support the bill.

But the deluge of "confused" calls from TikTok users to congressmen and senators may have backfired.

Several politicians say the campaign has worsened the concerns they have about the app, and strengthened their resolve to pass the legislation.

• What could a TikTok ban mean for creators?
• How a US TikTok ban will affect Gen Z

Is TikTok banned in other countries?

If the bill becomes US law, it could inspire similar moves elsewhere.

TikTok is already banned in India, which was one of the app's largest markets before it was outlawed in June 2020.

It is also blocked in Iran, Nepal, Afghanistan and Somalia.

The UK government and Parliament banned TikTok from staff work devices in 2023, as has the European Commission.

The BBC also advised staff to delete TikTok from corporate phones because of security fears.

How does TikTok work and how much user data does it collect?

At the heart of TikTok is its algorithm.

Users are offered three main feeds on their app - Following, Friends and For You.

The Following and Friends feeds present users with content from people they have chosen to follow and who follow them back, but the For You feed is automatically generated by the app.

This curated feed has become the main destination for users looking for new content, and creators hungry for the millions of views TikTok videos can clock up if they go viral.

Critics say the app collects more data than other social media platforms in order to power its highly personalised system.

This can include information about users' location, device, the content they engage with and keystroke rhythms they exhibit while typing.

But popular social media apps such as Facebook and Instagram collect similar data from users.This is a set of instructions within the app which determines which content is presented to users, based on data about how they engaged with previous material.