ASP.NET Core MVC Interview Question #160

What is the difference between returning JSON and returning a partial view?

Testing, AJAX/JavaScript Integration, Localization & Advanced MVC Senior Advanced

Quick Interview Answer

Returning JSON sends structured data that client-side JavaScript must interpret and render. Returning a partial view sends server-rendered HTML that can be inserted into the page directly.

Detailed Explanation

Returning JSON sends structured data that client-side JavaScript must interpret and render. Returning a partial view sends server-rendered HTML that can be inserted into the page directly.

JSON is useful when the browser owns more presentation behavior or data is consumed by multiple clients. Partial views are often simpler when the application is primarily server-rendered and only needs dynamic fragments.

Code Example

// JSON
return Json(new { id = product.Id, name = product.Name });

// HTML fragment
return PartialView("_ProductCard", product);