Where can you play master builders legally on the internet without minecraft as a download?
Free
How do you want to play on a Minecraft server without Minecraft? Lol That will not work
Stop on the internet
It's like asking "Where can I watch Youtube without internet?" or "Where can I play Minecraft without an electronic device?" Unfortunately, it makes absolutely no sense to ask such a question. Especially since my proposed questions would even be answered, for example. With friends, but you're asking for something that's impossible. Sorry