Logged in to check the same thing. We are serializing objects that can contain many nulls, and the size of the file is quite large. It would be very helpfull to remove the nulls as an option. Otherwise, at this point, we have no choice but use a Jackson custom serializer and check each field (e.g. if (foo != null) { jgen.writeStringField("foo", i.getfoo()). Not an ideal solution when our objects have dozens of private variables.