Is a bad idea to use Github Pages for a production ready app?

I'm trying to not spend money on hosting for a react app and I found this package:

  • gh-pages: Publish files to a gh-pages branch on GitHub (or any other branch anywhere else)

By adding this script you can build and push the code directly to gh-pages and publish your app in seconds:

"scripts": {
  "deploy": "gh-pages -d build"
}

Do you think is a bad idea to use Github pages as production?

GitHub Pages are subject to some specific bandwidth and usage limits, and may not be appropriate for some high-bandwidth uses.
GitHub reserves the right at all times to reclaim any GitHub subdomain without liability.
— Github Pages ToS

If you are fine with this, it’s ok to host there.

It also depends on where in "production" phase you are with your app. Is this something that is close to an MVP or some kind of start up product that you are testing and have lett than few hundreds of users / customers, I would say it is ok. But if this is some kind of enterprise product you are building I would suggest to think twice.

I think that just to test is fine but for production do not.

Others have already said this but by relying on a free service you are at the mercy of the service operators. If you want actual production worthiness then you have to pay for hosting so that the rug won't be pulled from under you.