C# System.Text.Json

There is many Json Serializer for .NET out there.

Microsoft used to depend on the Newtonsoft.Json (aka. Json.NET) library. However, since the .NET Core 3, Microsoft introduced their own json serializer in the System.Text.Json package.

The Michael Blog’s post published some benchmark on differences .NET Json Serializers. His benchmark show that the new System.Text.Json of Microsoft is not the fastest one, but the speed favor appears to go to the jil serializer. However interesting comments show some missing factors in his benchmark.

• Memory footprint usage is left out in the benchmark. So the benchmark is questionable in the multi-threading / big json scenario.
• The Wade Blog’s post show a Apple vs Orange in the benchmark of the Michael Blog’s post: the case insensitive options are not the same default value.
  • The Wade Blog’s post show also a massive improvement in memory footprint of System.Text.Json compare to the Newtonsoft.Json.
  • But in the speed benchmark, it left out the fact that the System.Text.Json is optimized for the Utf-8 encoding of HTTP message (not the Utf-16 encoding of the C# String) and conclude that the speed of System.Text.Json is only slightly faster than Newtonsoft.Json which is optimal for Utf-16.

My take away

I believe that Microsoft knows where they are going and capable to make the best .NET Json Serializer. They will improve further the System.Text.Json package evens if it is (questionably) not the fastest one right now. In addition, the System.Text.Json package is open source and will probably attract talented contributors. It’s time for me to migrate from the Newtonsoft.Json to this new System.Text.Json.