System.Text.Json vs Newtonsoft.Json – .NET 10 RC1 demo

Target: net10.0 (RC1). No preview flags required.

Run

dotnet run -c Release

Pick a menu option.

Highlights

• JsonSerializerOptions.Strict (duplicate-key detection, etc.).
• JsonSerializer.DeserializeAsync<T>(PipeReader) support.
• Source generation round-trip samples.
• Polymorphism + [JsonRequired], naming policy (snake_case), DateOnly/TimeOnly.