It depends on what you are intending to do with your Notebook: do you want that the user can recompute the results or just playing with them?
Static notebook
NBViewer is a great tool. You can directly use it inside Jupyter.
Github has also a render, so you can directly link your file (such as https://github.com/my-name/my-repo/blob/master/mynotebook.ipynb)
Alive notebook
If you want your user to be able to recompute some parts, you can also use MyBinder. It takes some time to start your notebook, but the result is worth it.
As said by @Mapl, Google can host your notebook with Colab. A nice feature is to compute your cells over a GPU.
