What tools are there to search the fediverse (across multiple instances) for certain hashtags?

For the short time it existed, #FediOnFire offered this. #FediWall can search several instances, but you have to specify which ones.

@FediTips

#fedihelp #help #fediverse #hashtags #mastodon

Searches already work across multiple instances, but they will be limited to the accounts and posts noticed by your instance (a list of what instances notice: https://fedi.tips/which-posts-and-accounts-can-i-see-from-my-server)

There is https://fedi.buzz which displays trending hashtags across a wide range of instances, with links to that tag on instances where it is trending below each tag.

#FediBuzz recently added support for #Fediwall and can be used as a source for hashtag searches. Just add "fedi.buzz" as a source. It takes a while before FediBuzz starts to return results, but once the caches are warm, it offers a great overview over the fediverse.

Interesting! Can you give an estimate how long it takes to populate the wall via fedibuzz? I was just trying fedi.buzz as the only source on your fediwall.social, looking first for hashtags of an academic interest, then for a hashtag that's currently trending on fedibuzz, and the fediwall stayed empty in both cases.

@FediTips

As far as I understand it, FediBuzz starts collecting posts with a given hashtag only after the first request to its API. So you'll only get new posts, the fediwall will be empty at first. But I'm not sure about the details.

Okay, thanks! Then I'll check back.

Are you wanting to use fedi.buzz as a relay? There's a separate page for that at:

https://relay.fedi.buzz

I'm not an admin. My goal is to find posts and accounts that use certain hashtags, beyond those that I (and my home instance) already know. For select instances I can do that via FediWall by @defnull - but I'm looking for tools that show me posts and accounts outside of my current "bubble".

Now I learned that Fediwall can use fedi.buzz as a source: Once FediWall requests a certain hashtag from it, fedi.buzz starts collecting those posts, which can then start to populate the Fediwall.