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Technology · head to head

Jenkins vs Ray

Jenkins logo

Jenkins

Technology

A self-hosted automation server that can build almost anything, through a plugin ecosystem that is also its main liability.

From
Free
Rated
-
Full reviewWebsite
Ray logo

Ray

Machine Learning

Scale AI and Python applications

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Jenkins the controller is stateful and, in the open source distribution, has no high availability: build history, configuration and plugin state live on one filesystem, so every plugin upgrade and core update is downtime for every team using it, and a controller disk failure is a restore-from-backup event.; Ray windows support is beta and multi node Ray clusters are untested on Windows
  • They diverge on capability: Jenkins covers Plugin ecosystem, Ray covers Distributed computing.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Jenkins and Ray actually diverge.

Attributes where Jenkins and Ray differ
AttributeJenkinsRay
Pricing modelopen-sourcefreemium
PlatformsLinux, Windows, Macos, DockerLinux, Mac, Windows
CategoryTechnologyMachine Learning
Founded20112019

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Jenkins

  • Plugin ecosystem
  • Distributed agents
  • Declarative and scripted pipelines
  • Shared libraries
  • Configuration as Code
  • Credentials management
  • Self-hosted anywhere
  • Multibranch and organisation folders

Only in Ray

  • Distributed computing
  • Ray Train
  • Ray Tune
  • RLlib
  • Ray Serve
  • PyTorch
  • TensorFlow
  • Hugging Face

What people use each for

The jobs each tool is most often brought in to do.

Jenkins

  • Builds that must touch physical hardware, such as embedded devices, test rigs or signing modules attached to a specific machinenot Ray
  • Air-gapped or heavily regulated environments where a hosted CI runner cannot be used at allnot Ray
  • Toolchains that hosted CI does not support, including node-locked commercial licences for EDA, CAD or simulation softwarenot Ray
  • Organisations with years of existing Jenkins pipelines where the migration cost currently outweighs the operational cost of stayingnot Ray

Ray

  • Distributed AI model training and servingnot Jenkins
  • Large-scale data processingnot Jenkins
  • Reinforcement learning workloadsnot Jenkins
  • ML inference servingnot Jenkins

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Jenkins

  • The controller is stateful and, in the open source distribution, has no high availability: build history, configuration and plugin state live on one filesystem, so every plugin upgrade and core update is downtime for every team using it, and a controller disk failure is a restore-from-backup event.
  • Capability comes from around 1,900 community plugins of very uneven maintenance, and the Jenkins security team regularly publishes advisories for plugins whose maintainer has gone; in some cases the advisory itself states that no fix is available and the only remedy is to stop using it.
  • Plugin upgrades are coupled: one plugin can require a newer core or a newer version of another plugin, so applying a single security fix cascades into a coordinated upgrade of a dozen components on a timetable you did not choose.
  • Pipelines are Groovy running under a sandbox and a continuation-passing-style transformation, so ordinary Groovy constructs sometimes fail in non-obvious ways, and the debugging skill you build transfers to no other CI system.
  • It is free to licence and expensive to run: somebody must own the controller, the agents, the Java version, the credentials store and the plugin upgrade cycle, and that recurring staff cost is the usual reason organisations move to hosted CI even when Jenkins works.
  • Leaving is costly by construction, because shared libraries, plugin-specific pipeline steps and accumulated freestyle jobs have no mechanical translation into GitHub Actions or GitLab CI, so the migration is a rewrite whose price grows every year you defer it.

Ray

  • Windows support is beta and multi node Ray clusters are untested on Windows
  • Windows lacks copy on write forking, which raises memory requirements, and Ray code assumes UNIX filenames
  • Multi node clusters are untested on Apple Silicon Macs
  • The Java API is experimental and community supported only, and requires matching Java and Python versions
  • Python 3.13 support is beta

Pricing, plan by plan

Jenkins

Free
  • Open SourceFree
    • Unlimited builds
    • 1000+ plugins
    • Self-hosted
  • CloudBees CI$undefined/month
    • Enterprise features
    • High availability
    • Role-based access

Ray

Free
  • Open SourceFree
    • Full Ray framework
    • All libraries
    • Community support
  • Anyscale PlatformFree
    • Managed infrastructure
    • Enterprise support
    • SLAs

Which should you pick?

Choose Jenkins if

  • You need plugin ecosystem.
  • You want to start without paying.
  • You work on Linux, Windows, Macos, Docker.
  • You also want distributed agents.
Jenkins review

Choose Ray if

  • You need distributed computing.
  • You want to start without paying.
  • You work on Linux, Mac, Windows.
  • You also want ray train.
Ray review

Questions people ask

Is Jenkins or Ray better?
Neither clearly leads. Jenkins starts at Free and Ray at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Jenkins or Ray?
Jenkins starts at Free and Ray at Free.
Does Jenkins or Ray run on more platforms?
Jenkins runs on Linux, Windows, Macos, Docker. Ray runs on Linux, Mac, Windows.
Can I use Jenkins for free?
Both have a free tier, so you can try either at no cost before committing.
What is Jenkins best used for?
Jenkins is most often used for builds that must touch physical hardware, such as embedded devices, test rigs or signing modules attached to a specific machine, air-gapped or heavily regulated environments where a hosted ci runner cannot be used at all, toolchains that hosted ci does not support, including node-locked commercial licences for eda, cad or simulation software, organisations with years of existing jenkins pipelines where the migration cost currently outweighs the operational cost of staying. Of those, builds that must touch physical hardware, such as embedded devices, test rigs or signing modules attached to a specific machine and air-gapped or heavily regulated environments where a hosted ci runner cannot be used at all are not what Ray is typically brought in for.
What can Jenkins do that Ray cannot?
Jenkins covers Plugin ecosystem, Distributed agents, Declarative and scripted pipelines, Shared libraries. Ray covers Distributed computing, Ray Train, Ray Tune, RLlib.

Answered from the vendors’ own pages

Jenkins: Why choose Jenkins over GitHub Actions or GitLab CI?

When the build needs something hosted runners cannot give you: physical hardware, an air-gapped network, a node-locked commercial tool licence, or an unusual platform. If none of those apply, hosted CI is usually less work to own.

Ray: Is Ray free?

Yes. Ray is free and open source software with over 34,800 GitHub stars and 1,000+ contributors. Users can download and use the Ray framework at no cost.

Source
Jenkins: Can Jenkins run in high availability?

Not in the open source distribution, which runs a single active controller. High availability and active-active controllers are features of CloudBees' commercial products. Open source deployments mitigate it with fast restores and, sometimes, multiple independent controllers.

Ray: Is there a paid option for Ray?

Yes. Anyscale, the managed platform built by Ray's creators, offers paid tiers with enterprise features like governance and advanced tooling. Specific Anyscale pricing details are not listed on the Ray website.

Source
Jenkins: How risky are the plugins?

This is the main operational risk. Many plugins have a single volunteer maintainer, and Jenkins publishes security advisories for unmaintained plugins where no fix exists. Auditing which plugins you depend on and who maintains them should be a periodic task, not a one-off.

Ray: Can I try Ray with credits?

Yes. New users can try Ray with $100 credit on Anyscale's managed platform to explore the service.

Source
Jenkins: Do I need to know Groovy?

For declarative pipelines you can go a long way without it. Anything involving shared libraries, conditional logic or custom steps is Groovy, and it runs in a sandboxed, transformed environment where standard Groovy idioms sometimes behave unexpectedly.

Jenkins: What does it cost?

The software is free under the MIT licence. The cost is infrastructure and staff time to run controllers, agents and upgrades, plus a CloudBees subscription if you want high availability, support or centralised management of many controllers.

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