Slack, the San Francisco-based communication startup, today announced that it has officially raised $160 million in a new funding round, bringing its war chest up to $340 million and a valuation of $2.8 billion. 

Slack\’s new investors include Institutional Ventures Partners, Horizons Ventures, Index Ventures and DST Global. In October 2014, it raised $120 million in fresh fund with a $1.2 billion valuation led by Kleiner Perkins Caufield & Byers and Google Ventures. Earlier investors include Andressen Horowitz, Accel Partners and The Social+Capital partnership. Overall, the company has raised $340 million.

Launched in 2009, Slack is a San Francisco-based team communication tool, it offers one-on-one messaging, private groups, persistent chat rooms, direct messaging as well as group chats organized by topic. Slack also integrates with a number of third party services, including Google Docs, DropBox, Heroku, GitHub and Zendesk. Its customers include Adobe Systems, Live Nation, The New York Times and PayPal

Slack, which competes with Atlassian, Yammer, Convo and Bitrix24, has been busy rolling out features in the past few months. Last month it brought its app to Windows platform, and recently it announced that it was making a two-factor authentication available for users. 

The company, led by CEO Stewart Butterfield, has more than 200,000 paid users and 750,000 daily users. 

Image Credit: The American Genius