System.Text.Json vs. Newtonsoft.Json: Which One Should You 💻Use in .NET

JSON (JavaScript Object Notation) has become the backbone of data exchange in modern web and API-driven applications.

For years, Newtonsoft.Json (commonly referred to as Json.NET) has been the go-to library for JSON handling in .NET. Its extensive feature set and flexibility have made it a favorite among developers. However, with the introduction of System.Text.Json in .NET Core 3.0 — and its continuous enhancements in .NET 9— it’s clear that Microsoft is positioning it as the default JSON library for .NET applications.

This shift begs the question: Should you stick with Newtonsoft.Json, or is it time to adopt System.Text.Json for your .NET projects?

In this blog, we’ll compare these two powerful JSON libraries based on performance, features, ease of use, and compatibility. Whether you’re building a brand-new application with .NET 9 or maintaining an older project, this guide will help you make an informed decision.

Let’s dive in and explore the strengths and weaknesses of each library to determine which one best fits your needs.

1. Performance

• System.Text.Json: Built into .NET Core 3.0+ and .NET 9.0, it is highly optimized for performance, offering faster serialization and deserialization, and lower memory allocation.

System.Text.Json Example: Serialization and Deserialization

• Newtonsoft.Json: While slower than System.Text.Json in most benchmarks, its performance is still adequate for many applications.

Newtonsoft.Json Example:

🚀Choose System.Text.Json if performance is a top priority.

2. Features

• Newtonsoft.Json:
• Rich feature set, including advanced LINQ-to-JSON querying, JSON schema validation, and custom serialization.