Nbviewer.jupyter.org not working

Hi,
I am not sure whether this is the right place to post this, but maybe someone can help me.

I am using Jupyter notebooks for teaching Julia, posting notebooks on Github where my students can open and download them. For viewing the notebooks on smartphones, I always provide them a nbviewer.jupyter.org link as well. It seems however that https://nbviewer.jupyter.org/ is not working:

Error 503 No healthy backends

Does anyone know what’s happening?

EDIT (16.10.2019): As soon as I posted it, the problem has been solved. If you have any ideas for alternative services, let me know. Viewing the notebooks in Github also doesn’t work most of the time. So that’s not a solution for me.

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I have the same problem, my ipynb is fine and functional on my local machine, and it was also rendering fine on github before i ran it to display outputs. Now that I have ran it with outputs then pushed, its displaying this error:

Several things:

A

First and foremost is what you are sharing in your screenshot is not nbviewer, which is the topic of this thread. The Jupyter Community doesn’t have any input or control into the GitHub-rendered preview they offer for developers. (You’ll note that I stress preview there. That is because it is simply provided as a preview for developers. This used to be more apparent when GitHub wouldn’t even attempt to render their preview for a notebook of it was over 100 kb. They would instead show a note referring users to use nbviewer. And so new users quickly learned to use the much more capable, feature-rich solution provided by the Jupyter Community for viewing ‘static’ notebooks. ‘static’ also needs explaining because nbviewer is capable of actively displaying interactive things that have javascript underlying them, such as Plotly plots. GitHub’s preview doesn’t do that as this time. And unfortunately because GitHub’s preview has been made a bit more capable over time, though still nowhere near approaching the abilities of nbviewer, new users don’t learn as quickly what they are seeking to render and share public ‘static’ notebooks files.)
The Jupyter Community have invested a lot in making their nbviewer rendering capable, feature-rich and the one you should share with non-developers.

B

Normally, it is helpful for you to get specific insights to share a link to the repo or gist you are discussing with those trying to help you.

However, I see that GitHub is having an issue if you try to view any notebook in their preview right now. Example:

one of the MyBinder preview notebooks, displayed above, shows the same thing you show. That file has been sitting there for four years and so it is not an issue with the file or how it was uploaded.
So as the example shows, please look at other examples online to discern if it is something you did or something in the system that you usually will need to wait until GitHub fixes in that case.

C

Back to nbviewer

nbviewer is currently working just fine, and so I am just posting links the the nbviewer renderings. Plus, the capabilities of the nbviewer renderings are more readily apparent when you use the service anyway.
Examples:

Click here to see nbviewer rendering of the MyBinder example notebook I referenced above

You can get a nbviewer URL for any public notebook you have. For, the GitHub examples go to nbviewer and paste the URL in the form.
You’ll note if you examine the URL for the nbviewer renderings, which are just pointing at the GitHub contet, you can see they form a pattern and you can this adapt a GitHub URL by hand to follow that pattern without needing to use the form, if you’d like.

Other examples:

See how Plotly plots render nicely if you scroll to the bottom here at this nbviewer rendering.

This example is from here where I point out that GitHub’s preview doesn’t handle Plotly, unlke nbviewer. There are other examples of types of things, such as animations made of frames using’FuncAnimation(), that nbviewer is capable of displaying that the more limited GitHub preview doesn’t attempt to display, even when GitHub is working normally.

This one makes it more obvious:
The plots in this example shows 3D Plotly plots remain remain fully rotatable in nbviewer.

This example better illustrates Plotly plots remain interactive in the nbviewer rendering. You’ll see the 3D plots remain fully rotatable in the nbviewer rendering. And so the rendering by nbviewer of ‘static’ Jupyter notebooks isn’t static, and in fact remains interactive for certain types of output. Plotly being one example of several.

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Its the notebook in this repository: https://github.com/Thabhelo/car-price-prediction

Thank you for your response, I learnt a lot from that detailed expanation.

So basically, I should not worry much about it displaying that as long as its opening and wrling fine on Jupyter?

Exactly. It looks like the glitch on GitHub has been sorted and the preview they offer renders now. See here.

The rendering here at nbviewer of your notebook looks cleaner and less overwhelming to those not used to coding. All your content works in both places; however, that won’t always be the case and the nbviewer should always offer a richer rendering. To get the nbviewer rendering, all you need to do is change the front end of the URL. Occasionally, you’ll come across repos, such as here, that even include a link to the nbviewer rendering as a badge that says ‘render nbviewer’.

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