PS it's a misconception that it's going to take a long time to get. You could find a school doing the testing this week and go in and take all the tests in 1 day if they'll allow it. Chances are you'll pass some, if not all. If you fail just the math, for example, then you can do some pretests on your own to practice or if you completely bomb you can get tutoring and special help. If you're already somewhat smart in most areas (can write an essay, can do some simple algebra) in theory you could just go take the test right now.
GED as far as I know cannot be completed online. You have to go in, register, pay some fees, and the test is officially given. There's rules, you need to present a photo ID, etc. Online they have no way to really know it's you taking the test, therefore the GED would not be valid