As someone with a second-degree black belt in Okinawan Goju Ryu Karate, I’ve made martial-art training a big part of my life for the past 20 years. I’m equally committed to learning how to do things online. But I’ve always wondered: Is studying karate online a viable option for those who can’t get to a real school?

I’ve known my sensei, a 90-year-old WWII fighter pilot, for almost half of my life. When I asked for his thoughts on this question, his response was swift: “They’ve been doing that for years,” he said. “In the ’80s, they used to sell tapes you could watch, rewind and do whatever the guy on TV was doing.”

But these new online dojos are more interactive, I explained. Students can email an instructor and share video clips demonstrating their grasp of the techniques they’re studying. He acknowledged this step forward but pointed out a weakness. “You’re never going to develop a relationship like you and I have, Mr. Fruhlinger. Plus, who are you going to spar with?”

If you Google “learn karate online,” you’ll encounter a hodgepodge of sometimes-defunct websites and apps. Most I tried have little substance. Some were obvious scams, designed to take the money of those seeking a quick and easy black belt. After extensive research, however, I found three that felt like the real deal. My criteria: an active and responsive sensei, one who cared about the art form, and a curriculum that was easy enough for beginners to jump into.

While they’re no match for studying in person with a sensei, these sites are worth considering if setting foot in a dojo is impossible for you. Just remember: As good as these online schools may be, you’ll still need the discipline to put in the practice required.