Normally, posts on the social media platform are limited to 280 characters.
Twitter stated that the change was made in response to people using the platform to post images of longer announcements and direct followers to external newsletters.
The test will last two months and will involve a small group of writers from Canada, Ghana, the United Kingdom, and the United States.
The new feature aims to keep readers in the Twitter ecosystem by allowing them to see a headline and then click on a link to access the longer note.
“Writers have relied on Twitter since the company’s early days to share their work, get noticed, be read, create conversation – everything except the actual writing,” the company said, announcing the new Notes product.
The move follows Twitter’s acquisition of Revue, a Dutch newsletter start-up, last year.
It announced on Wednesday that Revue would be folded into the new Notes product, which will allow writers to embed gifs, photos, and other features into long-form essays that can be read on and off Twitter.
After their notes have been published, users will be able to edit them.
Dr. Laura Toogood, a social media expert, said the trial was a significant step forward for Twitter. She claims that the feature will encourage users to stay on the platform rather than linking to other websites that can host long-form content.
“With this additional capability, Twitter is now in a position to compete with some of the most popular blogging platforms and potentially attract a new audience and a different type of user,”
“It will also encourage existing users to blog on Twitter rather than on other websites, which will help them retain their audience.”
Following a trial with a small group of users, Twitter increased the maximum number of characters for tweets from 140 to 280 in 2017.
The latest move comes amid scrutiny of Twitter’s business prospects, as Elon Musk’s planned takeover raises questions about the company’s direction.
The company announced in April that it was working on an edit button, shortly after Mr Musk, who had requested such a feature, revealed that he had purchased a large stake in the company. Twitter stated that the two incidents were unrelated.
Mr. Musk has also stated that he believes there is potential in a subscription model in which users pay to use the platform.