How to enable case-insensitive property name matching with System.Text.Json

In this article, you will learn how to enable case-insensitive property name matching with the System.Text.Json namespace.

Case-insensitive property matching

By default, deserialization looks for case-sensitive property name matches between JSON and the target object properties. To change that behavior, set JsonSerializerOptions.PropertyNameCaseInsensitive to true:


The web default is case-insensitive.

var options = new JsonSerializerOptions
    PropertyNameCaseInsensitive = true
var weatherForecast = JsonSerializer.Deserialize<WeatherForecast>(jsonString, options);
Dim options As JsonSerializerOptions = New JsonSerializerOptions With {
    .PropertyNameCaseInsensitive = True
Dim weatherForecast1 = JsonSerializer.Deserialize(Of WeatherForecast)(jsonString, options)

Here's example JSON with camel case property names. It can be deserialized into the following type that has Pascal case property names.

  "date": "2019-08-01T00:00:00-07:00",
  "temperatureCelsius": 25,
  "summary": "Hot",
public class WeatherForecast
    public DateTimeOffset Date { get; set; }
    public int TemperatureCelsius { get; set; }
    public string? Summary { get; set; }
Public Class WeatherForecast
    Public Property [Date] As DateTimeOffset
    Public Property TemperatureCelsius As Integer
    Public Property Summary As String
End Class

See also