To find a list of area codes for the United States, navigate to a website such as CountryCode.org or AllAreaCodes.com, select the United States from a list of countries, or peruse the area codes by U.S. states and cities. AllAreaCodes.com also provides an option to peruse area codes by navigating an interactive map of the United States.
On the home page of CountryCode.org, select the United States option from the drop-down menu, or click on the United States link in the alphabetized list of countries in the Country Codes section. Once the page loads, peruse the list of national and city codes on the website, or click on the download icon located in the first row to acquire the list as a CSV file.
On AllAreaCodes.com, open the image of the map of the United States that displays the area codes by clicking on the Enlarge Area Code Map link, or open an interactive version of the map by clicking on it directly. On the interactive map, use the mouse scroll wheel to zoom in and out, and drag the map by clicking and holding the left mouse button. To peruse a list of area codes, click on the Area Code Search by State link, and click on the desired state to view its area codes and the cities for which those codes apply.