Sentence examples for I'm joking from inspiring English sources

The phrase "I'm joking" is correct and can be used in written English
It is commonly used to indicate that the speaker is not being serious or sincere, and is instead trying to be lighthearted or humorous. It can also be used to soften a statement that may be taken too seriously. Example: "I can't believe you actually thought I ate the last cookie. I'm joking, of course. I would never do that to you."