However, Facebook continues to be the world’s largest social network with 1.35 billion active monthly users.

In overall member growth, Pinterest took the lead with 57 percent growth while Facebook’s member base grew by 6 percent. Instagram, LinkedIn,Twitter, YouTube and even Google+ all grew faster than Facebook.

“Facebook has some major challenges to face,” Jason Mander, author of the GWI report, writes.

“Firstly, people are growing tired of it, with 50 percent of members in the UK and US saying that they’re using it less frequently than they used to (rising to 64 percent among teens),” he wrote.

The report further reveals that among those with Facebook accounts, 1 in 2 say they are actively using Facebook each month, “giving it about twice as many active users as the three sites which compete for second position: Twitter, YouTube and Google+.”

Facebook Messenger userbase reaches 500 million per month

Facebook now has about 500 million people using the messenger service every month.

US-based firm had originally started the messenger service as a chat feature on the website but later rolled it out as a standalone mobile app.

"Messaging is an important part of how people stay connected and since Messenger launch in 2011, we've been passionate about giving people a faster and more expressive way to communicate," Facebook Director of Product Management Peter Martinazzi had said in a blog post.

Using Facebook Messenger, users can send stickers or videos, take selfies and chat with groups.

"We've also continued to improve speed and reliability. Updates to Messenger ship every two weeks so it continues to evolve and improve," he added.