act vs Buildkite Agent
A side-by-side comparison of two self-hosted ci/cd & build options — licensing, setup difficulty, resource needs, and what each one replaces.
| Feature | act | Buildkite Agent |
|---|---|---|
| Deploy effort | Read-the-docs project | Under-an-hour setup |
| Health score | 98 · Excellent | 83 · Excellent |
| Category | CI/CD & Build | CI/CD & Build |
| License | MIT | MIT |
| Language | Go | Go |
| Setup difficulty | Easy | Medium |
| Min. RAM | 256 MB | 256 MB |
| Deployment | bare-metal, binary | docker, binary, bare-metal |
| GitHub stars | ★ 72,094 | ★ 1,078 |
| First released | 2019 | 2014 |
| Replaces | GitHub Actions | GitHub Actions, CircleCI |
What are act and Buildkite Agent?
act
act lets developers run GitHub Actions workflows on their own machine using Docker, providing fast local feedback before pushing. It reads the same workflow files used by GitHub so behavior closely matches CI.
- Local GitHub Actions runs
- Docker-based execution
- Reuses workflow files
- Fast feedback loop
Buildkite Agent
The Buildkite Agent is an open-source build runner that executes pipeline jobs on your own machines while Buildkite coordinates orchestration. It lets teams keep build infrastructure private and scalable.
- Runs builds on your own hardware
- Cross-platform agent
- Parallel job execution
- Artifact handling
act vs Buildkite Agent: key differences
Both projects are written in Go. Buildkite Agent is the more established project (first released 2014), while act arrived in 2019. Act has the considerably larger community, at 72,094 GitHub stars versus 1,078. Buildkite Agent lists first-class Docker deployment; act does not.
Why pick each one
Choose act if…
- Test CI before pushing
- Saves CI minutes
Watch out for
- Not all actions supported
- Docker required
Choose Buildkite Agent if…
- Released under the MIT license
- First-class Docker support for quick deployment
- Active community (1.1k GitHub stars)
- Written in Go
Frequently asked questions
Is act or Buildkite Agent better?
act is the stronger all-round pick: it has both the larger community and the simpler easy setup. Consider Buildkite Agent if its specific feature set fits your needs better.
Are act and Buildkite Agent free and open-source?
Yes. act is licensed under MIT and Buildkite Agent under MIT. Both can be self-hosted at no software cost.
Can I run act and Buildkite Agent with Docker?
act: check the project docs for container support. Buildkite Agent: yes.