Have you ever learned anything as complex as guitar from online tutorials?
Guitar is complex. There are millions of ways of playing just one chord. How can we approach it with as little dross as possible?
Complex tasks requires guidance from an experienced teacher to learn. Yes, there is much to be gleaned from online tutorials. You can learn photography, video editing, how to fix a door, or how to change the oil in your car. Your first consideration is to determine how complex the skill that you are trying to learn is. The more complex it is, the harder it will be to learn without a guide. It's doable, but will be tougher.
Guitar is a marvelously complex instrument. There is no one right way to learn it (and thank goodness for that). This means that if you attempt to learn guitar completely online, you have to be okay with slugging and trudging through tons of information, needle-in-a-haystack style, in search of the gems. It's doable, as long as you are able to set aside the need to be instantly gratified.
Do you care about having in-person support?
If you need camaraderie, like if you know that having other people around you who play guitar will help you learn faster (it will: It'll decrease the amount of time to get "good" at guitar), learning online will be tough for you.
If, however, you just don''t care about having support, you'll do great with learning guitar online. That said, I do have a recommendation for you: take everything you find about guitar, any article, lesson, or video, with a large grain of salt. Dismiss the articles that seem like they are too difficult for where you are at, and throw anything out that doesn't live up to your standards. If it seems confusing, it's probably the fault of the author, and not you.
80% of learning guitar on your own revolves around knowing when it's appropriate to approach a specific concept and when to let it go. For example, if you learn open chords before you learn barre chords, you'll have an easier time learning guitar. Similarly, you'll need to be on the lookout for lessons that are trying to teach you something that is completely impossible for you to do right now. Save these lessons for later, and don't attempt them now. You're begging for a beating if you do.
Combining face-to-face guitar lessons with learning guitar online
Many students who have come in for face-to-face lessons with me have tried online guitar lessons before. If the online guitar lessons worked for these beginners, I'd be out of a job. This is not to say that online lessons aren't effective, because for some people they most certainly are. What I am saying is that in order to be successful at learning guitar online, you need to have motivation, momentum, will-power, and self-discipline.
If you are your own support network, if you're ready to brave the wild world of online guitar lessons, do it and don't look back. I do have one humble suggestion for you if things get dicey: Consider that finding a kind and compassionate guitar teacher (either in person or via Skype guitar lessons) can help you massively if you get stuck. Plus, combining your lessons with your online research will make your experience far more enjoyable.