HTML5 custom data attributes (data-*) are used to store arbitrary pieces of metadata about an element. One way to store such metadata in data-* attributes is to create a separate data-* attribute for each piece of information you wish to store. This approach works well if there are only a few data-* attributes. However, at times you need to store a bunch of metadata in data-* attributes. In such cases instead of creating multiple data-* attributes you can create just one data-* attribute and store all the pieces of metadata as an object in JSON format. To that end this article illustrates how custom data attributes can be used to store JSON data in an ASP.NET MVC application.