WASHINGTON - Donald Trump promised his Truth Social platform would offer a home for free speech, an unfiltered way to reach people.

Six months later, the former US president's amplification of conspiratorial memes and messages after the FBI searched his Mar-a-Lago estate indicates that extremist content has flourished.

Still, with mid-term elections looming, an AFP analysis shows his new bullhorn may be far less politically relevant than his past pronouncements on Twitter and Facebook.

"His reach is much smaller," said Mike Rothschild, the author of a book on the QAnon conspiracy theory. "Truth Social is pretty much MAGA-only territory."

Trump's Aug 30 posting spree on Truth Social indicates a lurch toward the darkest corners of conspiracy theory, almost two years after he lost the presidency to Joe Biden.

Trump interacted with a meme that was shared in reply to a post highlighting the writings of "Q", the anonymous persona whose posts on fringe forums gave rise to QAnon and its baseless claims about a cabal of Satan-worshiping pedophiles including Hillary Clinton.

"Trump has certainly amplified Q content before. He had retweeted Q believers or memes over 300 times on Twitter," Rothschild said. "But he had never shared something directly connected to a Q drop before."

The meme Trump shared referenced "the storm", a mass unsealing of indictments promised in QAnon lore that would culminate in his return to the White House.

He also re-posted images that put the words "your enemy is not in Russia" over the faces of top Democrats, including Biden.

It was a sign of what Truth Social - and Trump's potential 2024 campaign - could look like as the Nov 8 mid-terms approach.

"Trump's most ardent supporters will follow him wherever he goes," said Caroline Orr Bueno, a postdoctoral research associate at the University of Maryland.

"So although his messages may be reaching a smaller audience, those who are still following him are likely a more hardcore group of supporters who may be more easily incited to violence."

Truth Social launched in February 2022 as Trump's response to his ban from Twitter and two-year-suspension from Facebook following the Jan 6, 2021 attack on the US Capitol.

But Trump has just four million followers on Truth Social - a far cry from the 88.8 million he had on Twitter or the 35.4 million he had on Facebook.

"It's almost entirely Trump supporters," said David Thiel, a researcher at the Stanford Internet Observatory, of Truth Social's user base.

Trump's Truth Social posts are regularly promoted on other platforms popular with his supporters, such as Telegram and the far-right forum "The Donald", as well as on mainstream sites. Major Republican Party players also repeat his talking points.

But the direct pipeline to the public he had as president is gone.

Truth Social had 1.19 million monthly active users on Apple iPhones in July, according to data.ai, a company that tracks app metrics, compared with the 237.8 million daily active users Twitter counted in its latest quarterly report.

The app has been downloaded 3.08 million times globally since February, while Twitter and Facebook have logged 97 million and 341 million downloads respectively in the same time frame - and billions more in their existence.

"Even though Trump has this megaphone and is able to get attention for whatever new crazy thing he posts on Truth Social, it is several multiples less powerful than Twitter, several multiples less powerful than Facebook," said Jared Holt, senior research manager at the Institute for Strategic Dialogue, a non-profit London-based think tank focused on extremism. "It is a very closed feedback loop."

A loyal base of Truth Social users who express support for Trump and share misinformation about topics such as the 2020 election remains.

"Truth Social has become a refuge of sorts for people and content that have been banned from other platforms," Orr Bueno said.

NewsGuard, a service that tracks online misinformation, found 88 QAnon-promoting accounts with over 10,000 followers on Truth Social, including 32 that were previously booted off Twitter. Forty-seven of those accounts were verified by the Trump platform.

At least one app provider seems to have taken note. Google has not approved Truth Social for its store used by Android smartphone users, citing problems with content moderation.

"It appears to attract people with extremist views and then provides a safe haven where they can feed off each other without worrying about being reported or banned," Orr Bueno said.

"It's an environment that can be easily exploited by those seeking to incite violence or radicalise people."

Truth Social did not immediately reply to a request for comment. AFP