The regulator said it has put together the application based on data from EE, O2, Three and Vodafone.
The tool uses a colour coded system to show the type of coverage, and includes voice and data coverage, coverage on the inside and outside of buildings, and topographical information. Sometimes being in a valley or next to a hill can limit the coverage you can receive.
Ofcom wants people to check their own coverage experience and leave comments which it will use to refine the tool with a new version coming out this autumn.
Ofcom said that it will also continue to improve the process of making it easier to switch different mobile providers.
You can find the tool here and it looks like this.