SAN FRANCISCO — Joe Biden became @POTUS on Twitter slightly before noon on Wednesday. But unlike four years ago, when President Donald Trump took over the handle, Biden has not kept the account’s current followers.

The account he took over at midday Wednesday started with more than 955,000 followers, those who had followed his transition account @PresElectBiden in the last week. Trump’s POTUS account became @POTUS45 at the same time. The previous followers of the POTUS account will get a notification about the transfer with the option to follow Biden’s POTUS account if they wish.

Biden’s digital director Rob Flaherty called Twitter’s transition plan “profoundly insufficient” in a tweet last week.

“They’re bending themselves over backwards to break with the 2017 protocol they set on the transfer of accounts, and also breaking with every other social platform in providing the new administration a follower base,” he added.

https://twitter.com/POTUS/status/1351960433905700864

The move of accounts between administrations is one of a broader digital transition among social media accounts on Facebook, Twitter and YouTube taking place after Biden became the 46th president Wednesday.

The social media companies will hand over the keys to the White House accounts to the Biden administration after archiving them on Inauguration Day, ushering in what is expected to mark a different tone and cadence of the accounts after the past four years.

The Biden administration took over the @POTUS account on Twitter, as well as @WhiteHouse, @VP, @FLOTUS and @PressSec. On Facebook, the administration took over accounts for the White House and POTUS, and on YouTube they will inherit the White House channel.

Twitter declined to comment beyond its blog about the decision not to automatically move followers.

“These institutional accounts will not automatically retain the followers from the prior administration,” Twitter wrote in a blog post about the inauguration. “People on Twitter who previously followed institutional White House Twitter accounts, or who currently follow relevant Biden or Harris Twitter accounts, will receive in-app alerts and other prompts that will notify them about the archival process, as well as give them the option to follow the new administration’s Twitter accounts.”

Biden’s first tweet as POTUS was sent from the account at 12:36 p.m.

There is no time to waste when it comes to tackling the crises we face. That's why today, I am heading to the Oval Office to get right to work delivering bold action and immediate relief for American families.

— President Biden (@POTUS) January 20, 2021

“There is no time to waste when it comes to tackling the crises we face,” the tweet reads. “That’s why today, I am heading to the Oval Office to get right to work delivering bold action and immediate relief for American families.”

Trump’s POTUS45 account has more than 33 million followers. It and all its tweets will be archived Wednesday and preserved by the National Archives and Records Administration. Twitter will also create a new institutional account for the incoming administration: @SecondGentleman for Doug Emhoff, husband of Vice President Kamala Harris and the first male spouse in that role.

Trump has also been suspended “indefinitely” from Facebook, and YouTube confirmed Tuesday that it would extend his suspension there for at least another week. The historic crackdown by the social media companies came after years of increasing tension between the sites and Trump’s fiery rhetoric, which often included dangerous misinformation.

The final straw was the Jan. 6 attack on the U.S. Capitol that Trump failed to immediately condemn, leading the companies to shut down his social media access to try to prevent more violence.

YouTube will transition the White House account to the Biden administration, along with its 1.9 million followers. The videos from Trump’s administration have been removed from the page and will be moved to a new channel to serve as an archive, similar to the Obama White House channel.

Facebook and Instagram will archive Trump’s POTUS and White House accounts and turn over those usernames to Biden.

People who follow the current White House account will automatically follow it when Biden takes over, and people who follow Joe Biden’s current political accounts will also follow him on the POTUS handle. But current followers of Trump’s POTUS handle will not automatically follow that account under Biden.

“We’re following the same procedures we used during the transfer between the Obama and Trump administrations when President-elect Biden is sworn into office,” Facebook spokesperson Dani Lever said before the inauguration.

Biden will be the third president to use Twitter while in office, and he probably will not strike the same tone as Trump’s.

“Anyway, the nice thing about Joe Biden is that he truly couldn’t care less about Twitter followers. Or Twitter!” Flaherty tweeted last week.