Jenkins or GitHub Actions? How to choose the right CI/CD tool for your context

Jenkins is 18 years old. GitHub Actions launched in 2019. And if you’ve been in any engineering conversation lately, you already know what the default take is: Jenkins is legacy, GitHub Actions is the answer.

I’ve worked with enough teams to know that assumption is wrong often enough to hurt people.

What Jenkins does well

Jenkins has been around long enough that people know how to make it do almost anything. Over 1,800 plugins. A pipeline DSL that can handle complex, multi-stage, conditional workflows that are genuinely difficult to replicate cleanly in GitHub Actions.

More importantly: if you already have Jenkins, you have institutional knowledge, existing pipeline code, and a team that knows where the sharp edges are. That’s worth something.

Jenkins is still the right choice when you need to run jobs on machines you own — air-gapped networks, specialized hardware, on-premise infrastructure. When your pipelines have been running in Jenkins for years and the migration cost is higher than the benefit. When you have complex workflows with custom infrastructure requirements that don’t map cleanly to GitHub-hosted runners.

The decision to move off Jenkins should be driven by concrete problems, not trend-following. “It’s old” is not a business case.

What GitHub Actions does well

GitHub Actions integrates directly with where your code lives. No separate server to maintain. No plugins to update. No Groovy DSL to learn.

For a team that lives in GitHub — pull requests, issues, reviews, discussions — the integration is frictionless. Events in the repo trigger workflows naturally. Secrets are managed in the same place as the code. OIDC-based authentication to AWS, GCP, and Azure means you’re not storing long-lived credentials anywhere.

The marketplace has thousands of community actions for common tasks. Docker, Kubernetes, Terraform, cloud providers — they all have first-party or well-maintained community actions.

GitHub Actions is the right choice when you’re starting from scratch and your code lives on GitHub. When your team is small and can’t afford to maintain a Jenkins server. When your pipelines are straightforward CI/CD — test, build, deploy. When you’re optimizing for developer experience over operational flexibility.

The migration question

The most common context for this decision isn’t “which do I start with” — it’s “should I migrate from Jenkins to GitHub Actions?”

The honest answer requires a cost analysis. And most teams skip it.

Migration costs are real: rewriting Groovy Jenkinsfiles to GitHub Actions YAML isn’t a line-for-line translation, and that’s real engineering time. Reproducing custom plugins. Retraining the team. Handling the risk of breaking existing pipelines mid-transition. For complex pipelines, you’re looking at weeks to months of engineering time.

The benefits are also real: no more Jenkins server maintenance, patching, plugin updates, JVM performance tuning. Tighter GitHub integration. Potentially lower cost depending on your build volume.

Here’s my honest take: if your Jenkins installation is well-maintained, your pipelines are complex, and your team is productive with it — don’t migrate because someone told you Jenkins is legacy. The migration cost is high for a benefit that’s mostly operational aesthetics.

But if your Jenkins is poorly maintained, running on aging infrastructure, owned by one person who’s a flight risk, and the team finds it painful every single day — migrate. That pain is real and it compounds.

The cost model

GitHub Actions charges by compute minutes. Jenkins charges by infrastructure.

For a small team with low build volume, GitHub Actions hosted runners are almost certainly cheaper than maintaining a Jenkins server — even at cloud VPS prices. For a large team with high build volume, the calculation reverses fast.

Rough guide: if you’re running more than 30,000 build minutes per month, run the numbers carefully before assuming GitHub Actions hosted runners are cheaper. Don’t assume. Model it.

The hybrid approach

For teams mid-migration or with mixed requirements: GitHub Actions with self-hosted runners gives you the GitHub Actions workflow syntax and GitHub integration while running jobs on infrastructure you control.

This is the practical path I recommend most often. Migrate new pipelines to GitHub Actions on self-hosted runners. Let legacy pipelines keep running in Jenkins. Converge over time. No big bang. No risk concentration.

Making the actual decision

Ask yourself three questions. Be honest with the answers.

1. Where does your code live? If it’s on GitHub, GitHub Actions has a strong default advantage. If it’s anywhere else — GitLab, Bitbucket, self-hosted — evaluate tools native to that platform first.

2. Do you have complex existing Jenkins pipelines? If yes, quantify the migration cost honestly before you commit to anything. “Modern” is not a business case.

3. What’s your team’s operational capacity? If nobody has bandwidth to maintain CI/CD infrastructure, managed runners win on operational burden alone.

The right answer isn’t universal. It’s specific to your code location, team size, pipeline complexity, and operational capacity. Anyone who tells you otherwise is selling something.

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I work with teams building production systems and developer tooling. If this topic resonates, you can find more of my work at https://huntermussel.com.