Depends on the online school specifically, but in general, no, they are not considered a joke as nearly every brick and mortar school now also has an online component or full program attached to their school. Make sure they are accredited and are eligible for financial aid or veteran's benefits if that is relevant for you. Depending on what you are looking at getting your degree in, there are different schools that would likely be a better fit for you. There are a lot out there and a lot to sort through and they will be happy to fill your inbox with email and voice messages as soon as you start looking, but there are some good ones out there depending on what you are going for.