Jenkins

Jenkins remains worth using in specific contexts: when you have complex, highly customized CI/CD pipelines that leverage specific Jenkins plugins; when on-premises hosting is required for compliance or security; when migrating away would cost more than maintaining the existing setup; or when your organization has deep Jenkins expertise. For new projects, GitHub Actions, GitLab CI, or CircleCI are typically better choices — they're managed (no server maintenance), have modern UX, faster initial setup, and competitive free tiers. Jenkins' 1,800-plugin ecosystem provides unmatched flexibility for edge cases, but that same plugin sprawl creates maintenance burden and security patching overhead that modern managed CI/CD eliminates.

GitHub Actions is better for most new projects — it's integrated directly into GitHub, requires no server setup, has a generous free tier (2,000 minutes/month for public repos, unlimited for public), and uses simple YAML syntax. GitHub Actions works seamlessly with GitHub Pull Requests and has 15,000+ community actions in the marketplace. Jenkins is better for organizations with on-premises requirements, complex multi-technology pipelines leveraging specific Jenkins plugins, existing Jenkins investment, or environments not hosted on GitHub. The migration effort from Jenkins to GitHub Actions is significant for complex pipelines, so existing Jenkins users often stay, but greenfield projects almost always choose GitHub Actions today.

Jenkins itself is completely free and open-source — there's no licensing cost. The real cost is infrastructure and administration: you need servers to host the Jenkins controller and build agents (cloud costs ~$20–500/month depending on scale), plus DevOps engineer time to install, configure, upgrade, and maintain Jenkins and its plugins (often 5–20% of a senior engineer's time). CloudBees CI is an enterprise distribution of Jenkins (CloudBees, Inc.) with support, security patches, and management features — pricing starts around $25,000/year. For small teams, the free Jenkins is cost-effective; for teams without DevOps resources, managed alternatives like CircleCI or GitHub Actions have lower total cost of ownership.