In the graph above I’ve arranged the 28 Theeadiverse instances with at least 200 monthly active users (MAU)—orange instances running Lemmy, green Piefed, and red Mbin—on the basis of which instances they defederate.
I sourced the latest MAU figures from Fediverse Observer, with adjustments made to the totals for Piefed (due to undercounting by outdated instances, as noted here; I used @Vicinus@piefed.zip’s suggested estimate of 7,200 Piefed users) and Mbin (due to tardigram.com having a duplicate listing).
After adjustments, there are an estimated 43,287 monthly active Threadiverse users (35,184+7,200+903), of whom 87.84% are on the 28 largest instances.
Defederation data was sourced from Federation Checker. The tool doesn’t support Mbin instances, so I left fedia.io in its own category. If any defederations are missing, feel free to let me know. Ideally such a chart should also include community blocks to better illustrate which instances have to what, but that data doesn’t appear to be as easily searchable.
I also noticed cases of some instances being listed as being defederated by another instance, despite not appearing on the defederation list for that instance (i.e. reddthat.com and lemmygrad.ml are listed as being mutually blocked, despite neither having the other on their block lists). In testing that federation, I noticed that !wholesome@reddthat.com did not federate to Lemmygrad while !memes@reddthat.com did, so clarification on that matter would be helpful.
While I’ll update my generalized chart as needed to correct errors, perhaps at some point an automated federation mapping tool similar to the one feddit.de formerly hosted could be developed to more completely illustrate instance federation.


I was going to agree to disagree, but I couldn’t resist biting one more time because the link you posted turned out to be really interesting, but probably not for the reasons you were expecting… It’s past midnight where I live and I have work tomorrow so I’ll keep this one short.
Two things. First, just a reminder that like I wrote in my last message, I’m not arguing for any instance to re-federate Hexbear or Lemmygrad. It’s clear even just from reading this thread that most users don’t want to see them, and that’s actually a perfectly valid reason to maintain the status quo. But at this point it’s also pretty clear that ideological reasons and personal opinions are part of why those instances are so widely defederated and we are lying to ourselves if we insist otherwise.
Second, let me prove it by using your alt’s post you linked. I’ll be really frank here as you seem like someone who won’t take it personally. It’s obvious you feel very strongly about this matter, you’re good with words, and you’re not scared to influence others to adapt your ideals. Your post on discuss.online is honestly very well written if that was your goal. It’s manipulative, but not in instantly obvious way. It’s a textbook case actually: (All quotes below are directly from the post)
I could go on, but it’s late and I’m tired…
Then add what looks like a mountain of evidence, but is mostly a handful of trolls and douchebags, something you can find from almost any larger instance. Most people aren’t going to dig through the “evidence”, and just like that, discuss.online defederated Hexbear. It’s not my place to comment on the decision itself, especially since it doesn’t affect me. I’m just pointing what happened there.