is a search engine that automatically donates 50% of its revenue to charity, with users able to choose which charity they want to support.
It set up the competition as a way of incentivising charities to encourage their supporters to use the search engine.
More than 550 charities entered across the three categories of large, medium and small charities.
They were judged on how much they raised per supporter and on the imaginative ways they communicated their message.
Diabetes UK won the large charity category and the overall prize while The Arnold Foundation won the small charity category and the first runner-up prize of a local Clear Channel Outdoor campaign.
Cystic Fibrosis won the medium charity category and the second runner-up prize of free advertising on Everyclick.com.
The judges were: Polly Gowers, the founder of Everyclick; Pip Hainsworth, marketing director at Clear Channel Outdoor UK; Lindsay Boswell, chief executive of The Institute of Fundraising: and Daniel Farey-Jones, news editor at Brand Republic.
Gowers said: "Diabetes UK displayed incredible determination and drive in gaining momentum for its campaign and is a thoroughly deserving winner."
Diabetes UK's campaign will run in July and Everyclick will run its second Charity Challenge next year.