Michael Stanclift

How many Mastodon instances are there? How many active users are there? Depends on where you look and how you count.

Quick sanity check across datasources...

vmcrawl 
Instances: 9,226
MAU: 787,574

joinmastodon.org 
Instances: 7,952
MAU: 780,355

FediDB 
Instances: 9,193
MAU: 1,037,321

(Based on 20 Feb 2026 API data for all sources)

The world, may never know.

Feb 20 at 3:11amWeb
Show threadsteve mookie kongFeb 20
@[email protected] vmcrawl ftw
Show threadMichael StancliftFeb 20
@mookie
Show threadJames CridlandFeb 20
@vmstan Do we know that FediDB is only Mastodon instances? I'm suspecting it isn't.
Show threadcraftxboxFeb 20
@james @vmstan According to fedidb, yes.
Show threadMichael StancliftFeb 20
@craftxbox @james yeah, that was from an API call to their /software/mastodon endpoint.
Show threadJames CridlandFeb 20

@vmstan @craftxbox Ah, yes. https://fedidb.com/software

Well, then.

Show threadMichael StancliftFeb 20
@james @craftxbox something is not adding up. The total for Mastodon is higher than the total for all active users across all platforms.
Show threadcraftxboxFeb 20
@vmstan @james I do think FediDB has been the subject of various spoofing attacks in the past, I do recall a server that didn't really exist briefly showing up with twice the MAU of the entire network before they dealt with it.
Show threadNickFeb 20
@vmstan It's three.
Show threadNathan A. StineFeb 20
@vmstan a man with 1 data source always knows how many instances there are. A man with 2 or more never knows.
Show threadJL Johnson Feb 20
@vmstan seems to me that’s a good thing
Show threadManc AvGeekFeb 20
@User47 @vmstan agreed - not knowing precisely how many instances and users there are is a feature, not a bug.
I'm just wondering - are those numbers purely for Masto, or do they include other Fedi services?
Show threadMichael StancliftFeb 20
@mancavgeek @User47 just Mastodon. If you include all of them the number is over 41K (about half of which are federated Wordpress and Ghost blogs)
Show threadJocelynephiliac Feb 20
@vmstan thats a lot of servers
Show threadslyborgFeb 20
@vmstan FediDB has always had questionable math going on. And I don’t know how you are aggregating the MAU counts. The official server reports it daily, so depending on when you pull the data that alone will be a variance.
Show threadMichael StancliftFeb 20

@slyborg the official shows up in daily batches but it's updated for the current data throughout, so in this case it should be reflective of what the latest it last saw.

FediDB, I can't figure out how that's so high, I wonder if there is a batch process broken somewhere because the total active across all platforms on the site is currently lower than what their API is reporting just for Mastodon. 🤔 Also if you do a sanity check on the per-server list there's nothing that would kick it over so high.