Since you are a black belt you should have a decent grasp at what your style is all about, what you have learned, what you are better at and then what you are not so good at. You should know what your teacher teaches and what you can still learn from him and that you should learn from him before looking somewhere else. You will pick what you are not so good at and what your teacher is not so good at and you will not be able to learn well in your school. Karate is a full system, that first teaches striking methods and then goes into joint locks, arm bars, etc. Look at your art as a whole and all that is contained in it and then see what you don't have. No teacher in any martial art teaches everything or is good at everything. That's when you branch out. Don't look at other styles though as the same is true for all other teachers too. To truly become good and well rounded you need to find a teacher who knows the things your teacher does not know so well or does not teach yet is still part of your style. That often takes time and a lot of research about people who teach in your area and who are available to you. You need to build on what you already have not just start over someplace else. It is a waste of time to learn slightly different variations of kicking if kicking is already your strength and works real well for you already. This is only for people who want to show off and show other martial artists how good they already are. So train in the things you don't know well.
I suspect that this is really troll bait. If not, I suspect the person got their "black belt" at a McDojo. Mostly likely as a kid and they're still fairly young.
I say this for two reason. First, one doesn't get a black belt in "karate". One earns it in a particular style of karate. Second, if they had earned a black belt at a respected dojo they wouldn't be asking this question. Rather they'd ask what they could do to complement their training and even then I suspect they'd have an idea of what would work well with what they already know.
Just a black belt?? Huh?! Man black belt is the beginning of learning the art! Why don't you continue karate and earn higher dan?! However if you do want a change opt for something of your taste. You must now have a fair knowledge of what your taste is. Maybe try some grappling like BJJ or judo.
Karate
Taekwondo is a great martial art, I do both karate and taekwondo so can reccomens them, they are both different; but some aspects can be similar, such as the kicks and things!
Before anyone starts ranting on this answer that they are hugely different; it will always depend on your class/ teacher!
Hope this helps somewhat
-Joe
I would see what style, techniques, and discipline you would enjoy getting into. I would look into MMA and see if you see anything there
I recommend Judo.
I'm a black belt in karate and I would like to do another martial art for a change, any suggestions? I'm open to any martial art!
