How to Serialize enums as strings in .Net Core

If you try to serialize an enum to Json using System.Text.Json in .Net Core, it converts it into an integer by default.

public enum Seasons
{
    Unknown,
    Spring,
    Winter,
    Autumn,
    Summer
}

var seasons = Enum.GetValues<Seasons>().ToList();

When you serialize the list of seasons using the serialize method, i.e. JsonSerializer.Serialize(seasons), it gives an output of [0, 1, 2, 3, 4].

As you can see, this is not very readable and almost meaningless unless you look at the code.

To overcome this, you can specify a built-in converter to do the conversion to strings and pass it into a JsonSerializerOptions object.

var SerializerOptions = new JsonSerializerOptions
    {
        PropertyNameCaseInsensitive = true,
        Converters = { new JsonStringEnumConverter() }
    };
    
JsonSerializer.Serialize(seasons, SerializerOptions);
};

This will give an output of ["Unknown", "Spring", "Winter", "Autumn", "Summer"] which is much more readable.

You can use the same converter for deserializing the enum.

var seasons = JsonSerializer.Deserialize<T>(json, SerializerOptions);

This gives an output of [Seasons.Unknown, Seasons.Spring, Seasons.Winter, Seasons.Autumn, Seasons.Summer]

Conclusion

Using the built-in JsonStringEnumConverter, we can get a more readable output in our JSON.