ASP.NET MVC Single checkbox generates two values

So a single checkbox:

Will generate two input fields in MVC CheckboxFor:

It is because the browser does not post a checkbox when the value is false. MVC takes this into account and creates a dummy field for the case when the checkbox is unchecked. So when the checkbox is checked you get ‘true,false’ instead of ‘true’

TryUpdateModel will take this all into account and work out the correct value for you.