Twitter is testing allowing tweets to be expanded to 280 characters - double the existing limit - in the latest effort to boost flagging growth at the social network.

San Francisco based Twitter said on Tuesday that the new limit, a major shift for the messaging platform known for its 140-character tweets, aims to address "a major cause of frustration" for many users.

Twitter chief executive Jack Dorsey fired off what may be one of the first expanded tweets.

"This is a small change, but a big move for us," he wrote, calling the previous limit was an "arbitrary choice”.

"Proud of how thoughtful the team has been in solving a real problem people have when trying to tweet," Dorsey added.

A "small group" of users will see the new limits before Twitter decides on rolling out the changes more broadly, the company said.

"Trying to cram your thoughts into a tweet - we've all been there, and it's a pain," product manager Aliza Rosen and software engineer Ikuhiro Ihara said in a blog post. "We're doing something new: we're going to try out a longer limit, 280 characters, in languages impacted by cramming."

Twitter planned to leave the old limit in place for tweets in Japanese, Chinese and Korean because internal data showed written characters in those languages packed plenty into the allotted space.

"Our research shows us that the character limit is a major cause of frustration for people tweeting in English, but it is not for those tweeting in Japanese," Rosen and Ihara said.

"Also, in all markets, when people don't have to cram their thoughts into 140 characters and actually have some to spare, we see more people tweeting."

Twitter, which became a public company in 2013, has never reported a profit, even though it has built a loyal base of celebrities, journalists and political figures, including prolific tweeter US President Donald Trump.

In its most recent quarter, Twitter reported its base of monthly active users was unchanged at 328 million compared to the first three months of the year and up just five percent from a year earlier.

Its growth has failed to keep pace with social network leader Facebook, which has some two billion users, and Facebook-owned Instagram, with 800 million.

Making it easier

"We're hoping fewer tweets run into the character limit, which should make it easier for everyone to tweet," Rosen and Ihara said in the blog post.

"We understand since many of you have been tweeting for years, there may be an emotional attachment to 140 characters... But we tried this, saw the power of what it will do, and fell in love with this new, still brief, constraint."

Twitter has been seeking to draw in users by offering more video, including live streaming of sporting events, aiming to broaden its appeal.

"More is better; no doubt," Gartner analyst Brian Blau said of expanding room in tweets. "It is still not a lot of content, but you can put a lot in there."

And Boy, Twitterati did have a field trip

(Feature image source: Twitter/Design: Chhabi Parmar/ScoopWhoop)