If you want to transfer your course credits toward an undergraduate or graduate degree, you are less likely to be successful than if you tried to transfer traditional classes.
There are no hands-on courses, such as biology labs or drawing classes, available online.
You will not get direct interaction with the other students or the instructor. If you are struggling with any topics in the class, it may be harder to get help.
You will have to already be skilled at managing your time without any direct supervision to be successful in online courses.
Costs per credit are usually more for online courses.
Not only will you need to make sure that you have the technology skills to be successful in online courses, you will also need to make sure you have the right computer. You may also want to make sure that you have access to a secondary computer should something go wrong with your computer.