Jessie J had to postpone the start of her online birthday concert on Friday after suffering a string of technical difficulties.

To celebrate turning 27, the Brit planned to perform for fans live on Instagram at 3pm EST, with the Let's Get Live Staying Inside gig designed to raise funds for officials at the World Health Organization and United Nations Children's Fund (UNICEF) to aid those impacted by the spread of Covid-19.

However, Jessie's show got off to a rough start as she struggled with a series of sound issues.

"Just having some technical difficulties. Talk amongst yourself, please!" she told viewers at the top of the home concert.

She then opened with Masterpiece, but continued to battle audio problems, forcing her to cut short the livestream to fix her setup.

"Well, this is a great show so far!" she quipped.

Jessie, wearing a wig and a sparkly purple catsuit, returned around 20 minutes later, and addressed fans who had tuned in, admitting staging the charity show from her Los Angeles house without her usual team on hand was strange and challenging.

"This may be the funnest and weirdest thing I've ever done...," the birthday girl confessed.

Jessie then shared a few words of love and encouragement with her followers, as she urged them to join her in having a little fun.

"Wherever you are in the world I just want you guys to know that I'm thinking of you, and in this weird time, we have to do whatever we can to lift each other up...," she said.

The singer went on to belt out tracks including Flashlight, Bang Bang, and Domino, and later apologised for her "imperfect vocals", admitting she hadn't performed live for a while.