The number of forks of the repository, as reported by GitHub at the moment of collection.
API field
forks_count
Formula
Read directly from the API. Not derived.
Unit
forks
How to read it
A rough signal of how many people wanted to change, vendor or continue the code. It is not a quality measure and it never decreases when a fork is deleted.
What it does not mean
Forks include mirrors, vendored copies and forks created to open a single pull request, then abandoned.
A deleted or private fork is not subtracted from the count.
A high fork count can mean 'actively contributed to' or 'abandoned by everyone', and the number cannot tell you which.