The service has gone live with lenders including NatWest and Santander allowing borrowers to complete product transfers or remortgage to any of the other lenders on the panel.
It compares products from the existing lender with other deals on the market with borrowers able to choose whether to apply direct to a lender online or via a broker.
The comparison site is using Koodoo technology to operate and said more lenders would be joining shortly.
Compare the Market said it will continue to show intermediated mortgage deals for those customers who wish to use advice.
Mark Gordon, director of money at Compare the Market said: “The remortgage process can be time consuming and our new service will ensure that homeowners can get the best value for money by looking online.
“This service is designed for homeowners looking to remortgage onto similar deals. Compare the Market will continue to offer intermediated mortgage deals for those people who wish to seek advice.”
Koodoo chief executive and co-founder Seb McDermott added: “We are delighted to add Compare the Market to the platform, its scale and deep understanding of customer needs will help enhance the service we provide to our lender and broker partners.”