Ecosia, the world's largest not-for-profit search engine, released a browser extension today that aims to help plant millions of new trees without costing you a dime.

The extension is called freetree(Opens in a new window), and it's completely free to use. Once installed, freetree will pop-up when you're shopping on an affiliated online store for you to click to activate it. After that, completing your purchase sees a small commission (for referring you) go to Ecosia who then uses 100% of the money earned to plant trees.

Ecosia says using freetree won't cost consumers any more money on purchases, and is available to users in the US, UK, France, and Germany. A partnership with global market affiliation network AWIN should allow it to work with a wide range of online stores, and the average commission earned by freetree is 5%.

Christian Kroll, founder and CEO of Ecosia said, "We want to make it as effortless as possible for people to be climate active every day. With freetree, we’re enabling people to plant trees at no extra cost even as they purchase something online, whether it’s booking a summer holiday or buying a ticket for a gig."