Joker and clown differ in meaning, usage, and positive and negative meanings.
Meaning: Joker means witty, joking, (card) wild, etc.
Clown means to be a clown, a rude and stupid person, etc.
Usage: When used as a common noun, both can refer to people who love to joke. But their use scenarios and meanings are different, and the positive and negative meanings are also different. In general, joker is often used for figurative language jokes, which can be frivolous or humorous, so the scene is mostly neutral or positive. Clown, on the other hand, is mostly used to describe the funny in dress or behavior, and the scene is mostly neutral or derogatory.
Joker also has the meaning of "foreshadowing", while Clown does not have this meaning.
Positive and negative meanings: joker generally has a positive meaning, while clown has a derogatory meaning.
In summary, joker and clown have different meanings and usages, so choose the right words for your specific context.
he is always the joker in the group, *everyone laugh with his witty remarks.(He's the pistachio in the group, and he always makes everyone laugh with his witty words.) ）
she is not just a clown, but a highly skilled performer who can captivate an audience with her antics.(She's not just a clown, but a skilled performer who captivates audiences with her antics of sorts.) ）
he has a knack for turning any situation into a joke, *him the ultimate joker among his friends.(He has a knack for turning any situation into a joke, making him the ultimate pistachio among friends.) ）
she is known for her outrageous costumes and zany antics, *her the class clown everyone loves to hate.(She's known for her outrageous costumes and antics, making her a beloved clown.) ）
he has a way of **everyone feel special, even when he's the joker in the crowd.(He has a way of making everyone feel special, even if he's just a pistachio in the crowd.) ）
she is the life of the party, always upstaging everyone else with her hilarious antics as the class clown.(She's the focal point of the party, always stealing the show from others with her clown antics.) ）
he may be the joker, but he has a serious side that few people see behind his jokes.(He may be a pistachio, but few people get to see the serious side behind his jokes.) ）
she may play the clown at times, but she is actually very talented and has a serious side that few people know about.(She sometimes plays the clown, but she's actually very talented, and few people know her serious side.) ）