Workflows
Build matrix
Quick answer
A build matrix is a GitHub Actions feature that expands one job definition into many parallel jobs across combinations of variables such as OS and language version.
A build matrix is a GitHub Actions feature that expands one job definition into many parallel jobs across combinations of variables such as OS and language version.
Why it matters
Matrices are the fastest way to add parallelism and the fastest way to accidentally multiply your bill — three OSes by four versions by two architectures is 24 jobs.
Your next build could be twice as fast, at half the price
Start free. Migrating away is the same one line, and we publish that diff too.
Related
Artifact retentionArtifact retention is the period GitHub keeps workflow artifacts before deleting them, defaulting to 90 days and configurable per repository or per upload.Composite actionA composite action bundles several workflow steps into a single reusable action defined in YAML, without needing JavaScript or a container.Concurrency groupA concurrency group is a named lock that limits how many workflow runs matching that name can be in progress at once.Container jobA container job runs all of a job's steps inside a specified container image rather than directly on the runner.