A web mashup, or mashup website, is content that has been "mixed" or blended from different sources so that it can be presented in different ways. This is done using a web application that takes information from one or more sources and presents it in a new way or with a unique layout.

When the Nintendo Wii came out, it was hard to find in stores. A web mashup could have helped consumers by collecting data from various retailers like EB Games and GameStop, along with websites like eBay, and combining their information with Google Maps, so it could all be presented in an easy-to-use interface.

Trendsmap is an example of a popular mashup service. It combined Twitter’s trending topics with data from another Twitter trend site and displayed it on a map. Today, trends on Trendsmap are calculated using the service’s own algorithm.

Many mobile apps also function as mashups. For example, a restaurant app can combine menu information with location data to tell you what’s good to eat at nearby places.