Antonyms for the phrase "all joking aside" may include phrases like "no kidding", "seriously speaking", "without jest", "in all seriousness", "truth be told", or "frankly speaking". These phrases indicate a switch from a humorous or lighthearted tone to a more serious or earnest one. They suggest that the speaker is about to communicate something important or sincere, and that the listener should pay attention to what follows. While "all joking aside" can be used to indicate the end of a comedic moment, its antonyms often signal the beginning of a serious discussion or important revelation.