How can i configure JSON format indents in ASP.NET Core Web API

Question

How can i configure ASP.NET Core Web Api controller to return pretty formatted json for Development enviroment only?

By default it returns something like:

{"id":1,"code":"4315"} 

I would like to have indents in the response for readability:

{     "id": 1,     "code": "4315" } 

Answer 1

.NET Core 2.2 and lower:

In your Startup.cs file, call the AddJsonOptions extension:

services.AddMvc()     .AddJsonOptions(options =>     {         options.SerializerSettings.Formatting = Formatting.Indented;     }); 

Note that this solution requires Newtonsoft.Json.

.NET Core 3.0 and higher:

In your Startup.cs file, call the AddJsonOptions extension:

services.AddMvc()     .AddJsonOptions(options =>     {         options.JsonSerializerOptions.WriteIndented = true;     }); 

As for switching the option based on environment, this answer should help.

Answer 2

If you want to turn on this option for a single controller instead of for all JSON, you can have your controller return a JsonResult and pass the Formatting.Indented when constructing the JsonResult like this:

return new JsonResult(myResponseObject) { SerializerSettings = new JsonSerializerSettings() { Formatting = Formatting.Indented } };