Newtonsoft Json Dll [upd] -

var settings = new JsonSerializerSettings

In the sprawling universe of .NET development, few third-party libraries have achieved the ubiquity and lasting influence of Newtonsoft.Json (also known as Json.NET). For over a decade, it has been the default, instinctive choice for handling JSON—whether you were building a tiny console app, a massive enterprise web API, or a cross-platform mobile backend with Xamarin.

| Feature | Newtonsoft.Json | System.Text.Json | |---------|----------------|------------------| | Default property name casing | Preserved | camelCase | | Non-public members | Can serialize with opt-in | Not supported | | Dictionary with non-string keys | Serializes as JSON object | Throws or requires converter | | Cyclic references | ReferenceLoopHandling.Ignore | Not supported | | DateTime handling | ISO by default | Strict ISO (no legacy formats) | newtonsoft json dll

dotnet add package Newtonsoft.Json Or via Package Manager Console:

public class UnixDateTimeConverter : JsonConverter<DateTime> var settings = new JsonSerializerSettings In the sprawling

So pour one out for the DLL that refused to die. And then maybe add a reference to it, because your appsettings.json file still needs parsing. Have a Newtonsoft war story? A custom converter that saved your bacon? Share it in the comments below.

TypeNameHandling = TypeNameHandling.Auto ; (Warning: Only use this for trusted data—it's a security risk if you deserialize untrusted JSON.) Newtonsoft.Json is not the fastest library anymore. Microsoft's System.Text.Json is significantly faster, allocates less memory, and is more modern (using Utf8JsonReader and Utf8JsonWriter ). Benchmarks typically show System.Text.Json being 20-50% faster for serialization and 30-80% faster for deserialization. And then maybe add a reference to it,

Install-Package Newtonsoft.Json The DLL itself will land in your project's packages folder or be referenced via the .NET runtime's shared framework (if using the Microsoft.NET.Sdk ). Newtonsoft.Json is the COBOL of JSON serialization—not because it's old and crusty, but because it’s everywhere , it works , and rewriting what it powers would be a colossal waste of time. Its API is the mental model for JSON in .NET that an entire generation of developers grew up on.