IM is the fastest growing form of digital communication in the UK, with 43 per cent of people in Britain now using it at least once a week.
That number stood at just 28 per cent two years ago, according to the latest research on digital media habits from Ofcom.
Read more: We're a nation of "digital detoxers"
The popularity of WhatsApp and Facebook Messenger has exploded across the world, with both surpassing the one billion users mark this year, while Japan's Line - the sixth most popular messaging app in the world - went public in the biggest tech IPO of the year.
Photo and video messaging apps such as Snapchat also rose in popularity. They're now used by around one in five Brits, up from 14 per cent in 2014.
Use of email and SMS are on the decline - however, they are still the most common way we communicate, other than picking up the phone for a chat.
Some 70 per cent of people use email, down from 77 per cent two years ago, while 63 per cent text, down from 71 per cent in 2014.
While it's the most popular among those aged between 16 and 24, the research found IM was growing faster among those over the age of 25.
The nation spends around an hour a day sending emails, on average, and 48 minutes instant messaging. Social networking takes up 45 minutes a day while we spend just 21 minutes a day sending texts.
The research also found that we're a nation of so-called digital detoxers, with a third of us actively taking a time out from tech.