Full example from https://stackoverflow.com/questions/78112372

Program.cs

class Program
{
    static void Main()
    {
        Dictionary<string, object> dict1 = new Dictionary<string, object>()
        {
            {"Key1","1"},
            {"Key2",2},
            {"Key3","4"},
            {"Key4",3},
        };

        Dictionary<string, object> dict2 = new Dictionary<string, object>()
        {
            {"Key1","1"},
            {"Key2",2},
            {"Key3","3"},
            {"Key4",4},
        };

        List<KeyValuePair<string, object>> differences = GetDifferences(dict1, dict2).ToList();
        // Output (not necessarily in this order):
        // Key3: 4
        // Key4: 3
        foreach (var pair in differences)
        {
            Console.WriteLine($"{pair.Key}: {pair.Value}");
        }
    }

    public static IEnumerable<KeyValuePair<string, object>> GetDifferences(
        Dictionary<string, object> x, Dictionary<string, object> y)
    {
        return x.Except(y, new KeyValuePairComparer<string, object>());
    }
}

public class KeyValuePairComparer<TKey, TValue>
  : IEqualityComparer<KeyValuePair<TKey, TValue>>
{
    public bool Equals(KeyValuePair<TKey, TValue> x, KeyValuePair<TKey, TValue> y)
    {
        return EqualityComparer<TKey>.Default.Equals(x.Key, y.Key) &&
               EqualityComparer<TValue>.Default.Equals(x.Value, y.Value);
    }

    public int GetHashCode(KeyValuePair<TKey, TValue> obj)
    {
        return EqualityComparer<TKey>.Default.GetHashCode(obj.Key) ^
               EqualityComparer<TValue>.Default.GetHashCode(obj.Value);
    }
}