EDIT 3: All good now, the DNS has done its thing and defed.xyz is fully operational! Once again, thank you all for having checked out my tool, it means a lot to me.
Deploy problems, read more
EDIT 2: I’ve managed to fix it as well as add some optimization measures. Now it shouldn’t ramp up bandwith nearly as fast. The DNS records are still propagating for https://defed.xyz so that might not work, in the meantime you can use the free Netlify domain of https://sunny-quokka-c7bc18.netlify.app
EDIT 1: You guys played too much with my site and ended up consuming this entire month’s 100GB limit of free quota, so the site is currently blocked.
This is probably my most succesful project ever, thank you all for checking it out. It will take me some time to find another suitable host and move the project there.
ORIGINAL POST: I couldn’t find any tools to check this, so I built one myself.
This is a little site I built: the Defederation Investigator defed.xyz. With it, you can get a comprehensive view of which instances have blocked yours, as well as which ones you are federated with.
The tool is open source and available on GitHub. Hopefully someone will find it useful, enjoy.
In my experience, the data on there is significantly outdated/incorrect. The easy way to check is the domain reverse lookup- pick any instance (e.g. sopuli.xyz) and enter it into the reverse lookup. Then compare that to the official published list at sopuli.xyz/instances.
As of right now, FBA lists 9, while the official list is 15. The lists are significantly different as well, with each having multiple entries that are not on the other.
I have no idea how it works under the hood, but I guess there is some caching given how fast results are retrieved.