The best CI/CD tool depends on where your code lives and how you deploy: a pipeline built into your Git host suits most small teams, a self-hosted server suits teams that need control, and a GitOps tool suits Kubernetes. Eleven options follow in no particular order.
Continuous integration runs your tests every time someone pushes code. Continuous delivery takes the code that passes and gets it ready to release, or releases it. Together they're CI/CD, and they're the difference between nervous Friday deploys and boring, frequent ones.
The eleven tools below are listed alphabetically and in no particular order, from free open source engines to platforms built for large engineering organisations. Every description comes from the vendor's own site, read this week. If you're still building the team that will run the pipeline, my guide to finding remote DevOps talent may help.
CI/CD tools at a glance
In the free plan column, Yes means the tool's own site names a free plan, a free version, a free tool or an open source edition. Trial only means a time-limited trial. Not stated means the pages I read named neither, even where there's a button inviting you to try it.
| Tool | Type | Good for | Free plan |
|---|---|---|---|
| Argo CD | GitOps delivery for Kubernetes | Deploying to Kubernetes from Git | Not stated |
| Bitrise | Mobile DevOps platform | iOS and Android build pipelines | Not stated |
| Buildkite | CI platform with your own agents | Large monorepos and flaky tests | Trial only |
| CircleCI | Cloud CI/CD service | Keeping code tested around the clock | Not stated |
| GitHub Actions | Workflow automation built into GitHub | Projects already hosted on GitHub | Yes |
| GitLab CI/CD | CI/CD inside the GitLab platform | One platform from code to deploy | Trial only |
| Harness | AI-assisted delivery platform | Continuous delivery and GitOps at scale | Not stated |
| Jenkins | Open source automation server | Endless plugins and self-hosting | Yes |
| Semaphore | CI/CD with an open source edition | Fast CI with cloud or self-hosted options | Yes |
| TeamCity | CI/CD server from JetBrains | Teams already using JetBrains tools | Trial only |
| Woodpecker CI | Lightweight open source CI engine | A free, community-run pipeline engine | Yes |
Eleven CI/CD tools to consider
Argo CD
Best for: Platform teams on Kubernetes that want deployments driven declaratively from what's in Git, the GitOps way.
Bitrise
Best for: Mobile teams that want a CI/CD platform built around iOS and Android apps rather than a general-purpose server.
Buildkite
Best for: Engineering teams with big pipelines that want CI workflows, flaky test handling and package registries in one platform.
CircleCI
Best for: Software teams that want code kept tested, trusted and ready to ship around the clock with little hands-on effort.
GitHub Actions
Best for: Developers whose code already lives on GitHub and want CI/CD next to it, free for public repositories.
GitLab CI/CD
Best for: Teams that want source control, pipelines and security checks in the same platform, with a free trial to start.
Harness
Best for: Larger engineering organisations that want continuous delivery and GitOps with AI automation across many services.
Jenkins
Best for: Teams that want a self-hosted, open source automation server with hundreds of plugins for building and deploying almost anything.
Semaphore
Best for: Growing teams that want quick pipelines in the cloud, a hybrid setup or the open source edition on their own servers.
TeamCity
Best for: Development teams that like JetBrains tools and want a CI/CD server in the cloud or on premises, with a free trial.
Woodpecker CI
Best for: Small teams and hobby projects that want a simple, extensible CI/CD engine that's open source and free to run.
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Built into your Git host, hosted or self-run?
If your code is on GitHub or GitLab, the built-in pipelines are the shortest path. There's nothing extra to connect, and permissions follow your repositories. Hosted CI services add speed, caching and features for large test suites. Self-hosted servers give you full control over where builds run, which matters if code can't leave your network.
Mobile apps and Kubernetes are special cases. Mobile builds need macOS machines and signing certificates, which is why mobile-focused platforms exist. Kubernetes teams often split the job: CI builds and tests, then a GitOps tool deploys whatever is in Git.
Treat the pipeline as part of production
The NCSC's secure development guidance tells teams to carefully manage secrets and credentials, because deployment pipeline tooling may need secret tokens or credentials to launch and run code. It also says the code that triggers automated deployment to production should be carefully managed.
In plain terms, anyone who can edit your pipeline can probably ship to production. Lock down who can change pipeline files, keep secrets in a dedicated store rather than in the repository, and review pipeline changes the way you'd review application code.
Questions to ask before you switch
- Where does our code live, and does the tool connect to it natively?
- Do builds need to run on our own machines or network?
- How long does the test suite take, and can it run in parallel?
- Do we build mobile apps that need macOS runners?
- How are secrets stored and who can read them?
- Can we move our existing pipelines across without rewriting them all?
Signs your pipeline needs attention
- Builds take longer than a coffee break. Developers start batching changes.
- Flaky tests get rerun until they pass. Trust in the pipeline drains away.
- Only one person understands it. That's a holiday risk.
- Secrets sit in plain text. Move them before anything else.
Do you make CI/CD tools? Tool makers can ask to be considered for a featured place on this list.
My plain advice on picking a CI/CD tool
Start with whatever your Git host already offers and only move when you hit a real limit, such as slow builds or a need to run on your own machines. Switching CI tools is a lot of work, so the best reason to do it's a specific problem you can name.
Measure two things before and after any change: how long it takes from push to a green build, and how often the build fails for reasons that aren't your code. Those numbers tell you more than any feature list. If you're weighing who should run all this, my piece on modernising legacy systems covers the bigger picture.
Frequently asked questions
What does CI/CD stand for?
Continuous integration and continuous delivery or deployment. CI tests every change automatically; CD gets passing changes ready to release or releases them.
Which CI/CD tools are free?
Several tools in the table name a free tier or an open source edition on their own site. Check the free plan column for each one.
Is Jenkins still worth using?
Its own site describes it as a leading open source automation server with hundreds of plugins. It suits teams happy to host and maintain it themselves.
What is GitOps?
It's a way of deploying where the desired state of your system lives in Git, and a tool keeps the live environment matching what's in the repository.
Do small teams need CI/CD?
Yes. Even a simple pipeline that runs tests on every push catches mistakes early and makes releases less stressful.
How do I keep a pipeline secure?
Limit who can edit pipeline files, store secrets outside the repository and review pipeline changes like any other code change.
