Meta's Mark Zuckerberg went live with the Wednesday launch of Instagram's much-anticipated Threads platform, a clone of Twitter.

"Let's do this. Welcome to Threads," Zuckerberg posted on the app, along with a fire emoji.

While Threads launched as a standalone app, users could log in using their Instagram credentials and follow the same accounts, potentially making it an easy addition for Instagram's more than 2 billion users.

Threads' arrival comes after Zuckerberg and Twitter owner Elon Musk have traded barbs for months and even threatened to fight each other in a real-life mixed martial arts cage match in Las Vegas.

Musk bought Twitter for US$44 billion last October, but its value has since plummeted as it faced an exodus of advertisers amid deep staffing cuts and content moderation controversies.

"We're here to foster a positive and creative space for you to express your ideas. This time, it's all about conversation," said a post by the official Threads account.

"Investors can't help but be a little excited about the prospect that Meta really has a 'Twitter-Killer'," said investment platform firm AJ Bell.

But history is working against Meta. It has suffered multiple failures launching standalone copycat apps in the past, most notably its Lasso app aimed at competing with short video rival TikTok.