For full details about how this works, see Tracking Mastodon user numbers over time with a bucket of tricks on my blog.
https://instances.social/instances.json is a list of Mastodon instances, including their number of statuses and users.
This repo scrapes that and records the history of the file, a form of Git scraping.
You can use the git-history tool to build a SQLite database of the history of the instances:
pip install -r requirements.txt
# (or just pip install git-history)
./build-instance-history.sh
You can run that script multiple times and it will only update the database with new commits that have not been seen before.
You can also build a much smaller SQLite database of just the counts of users and statuses over time:
./build-count-history.sh
A script in this repository builds and publishes the counts.db database to S3. You can download the latest copy here - it's pretty small as it only records the total sum of users and statuses over time across all tracked instances.
https://scrape-instances-social.s3.amazonaws.com/counts.db
You can open this in Datasette Lite like so:
https://lite.datasette.io/?url=https://scrape-instances-social.s3.amazonaws.com/counts.db
Or visit this Observable notebook to see those figures plotted on charts:
https://observablehq.com/@simonw/mastodon-users-and-statuses-over-time