Jenkins

Jenkins is a free automation server that many sysadmins and DevOps engineers use to build software, run tests and deploy it on a schedule or on every commit. You describe the work as a job or as a Pipeline in a Jenkinsfile, Jenkins starts it on an agent and keeps the logs, artifacts and history. If you are looking for a Jenkins download, the project offers two release lines: the Long-Term Support (LTS) line, currently 2.580.2 (28 October 2026), and the weekly line, currently 2.589 (1 November 2026).

It is open source under the MIT licence and has been developed for many years, so most build tools, version control systems and cloud platforms have a plugin for it. The price of that flexibility is maintenance: you host Jenkins yourself, keep its plugins up to date and secure the server. We compare it with hosted alternatives in Jenkins vs GitLab CI vs GitHub Actions.

Jenkins at a glance

Last verified: 3 November 2026, on the Jenkins download page, the stable and weekly changelogs, the Windows and Linux installation pages and the LICENSE file on GitHub. Tested by us: Not tested yet. Steps below come from the official documentation.

What it does

• Runs freestyle jobs and Pipelines written as code in a Jenkinsfile, stored together with the project in Git.
• Starts builds on a schedule, on a webhook from your Git server or by hand.
• Spreads builds over agents (build nodes) on Windows, Linux or in containers, so one controller can serve several teams.
• Keeps console logs, test results and build artifacts for every run.
• Extends through plugins for source control, build tools, containers, cloud, credentials and notifications; the plugin manager installs and updates them.
• Manages users, permissions and credentials, and has a command-line interface and an API for automation.

How sysadmins use it

Build and test on every commit

1. Add a Jenkinsfile to the repository with stages such as build, test and package.
2. Create a Pipeline or multibranch job that points to the repository.
3. Add a webhook on the Git server so a push starts the job.
4. Publish test results and keep the built artifact as a build output.

Run nightly maintenance jobs

1. Create a job with a build trigger on a schedule (cron syntax).
2. Run a script on the right agent, for example a backup check, a report or a cleanup of old files.
3. Send a message when the job fails, using the plugin for your mail or chat system.

Keep the server itself healthy

1. Back up the Jenkins home folder (jobs, configuration, credentials) before every upgrade.
2. Update the controller and plugins regularly, because Jenkins publishes security advisories; the 2.588 weekly release and the 2.580.2 LTS release both contain important security fixes.
3. Do not run builds on the controller itself; use agents, and give each job only the credentials it needs.

Install and first run

Windows. Download the MSI installer for the LTS or weekly line (the 2.580.2 LTS MSI is about 57 MB). Install Java 21 or later first, run the installer, and choose a service account; the documentation recommends a dedicated local or domain user rather than the LocalSystem account. When the service starts, open http://localhost:8080, and unlock Jenkins with the password from the file initialAdminPassword in the secrets folder inside the install folder (by default C:Program FilesJenkinssecrets). Then install the suggested plugins and create the first administrator.

Linux. Install a Java runtime (the documentation example uses openjdk-21-jre), add the Jenkins package repository and install the jenkins package. The service runs under systemd; use systemctl status jenkins to check it. It listens on port 8080 by default; if the port is busy, set JENKINS_PORT with systemctl edit jenkins.

Docker. The project publishes Docker images; the handbook describes how to run a controller with a persistent volume for the Jenkins home folder, which you need so that jobs survive a container restart.

Checks and gotchas. Put Jenkins behind HTTPS (a reverse proxy is common) before exposing it. Choose the LTS line for a production server and the weekly line only if you need a new feature early. Check plugin compatibility after a major upgrade and take a backup first.

Limitations

• You host and maintain it: Java updates, controller upgrades, plugin updates, backups and monitoring are your job.
• Plugins are written by many authors and vary in quality; an abandoned plugin can block an upgrade or bring a vulnerability.
• The default web interface and job configuration feel dated compared with hosted services, although Pipelines as code reduce the amount of clicking.
• The controller needs Java 21 or later, so very old servers need a Java update before Jenkins can be upgraded.
• Not a deployment tool by itself: it runs the commands you give it, and the quality of the pipeline depends on your scripts and the plugins you choose.

Jenkins vs alternatives

GitLab CI and GitHub Actions keep pipelines next to the repository and need no separate server, which is simpler if your code already lives there; our comparison covers the cases where Jenkins still wins (mixed Git hosts, custom agents, complete control over the environment). For infrastructure rather than builds, look at Terraform or OpenTofu, and for configuration of servers after they exist, Ansible. More tools of this kind are in our DevOps and automation tools guide.

FAQ

Where is the Jenkins download?

On the official download page jenkins.io/download. It offers the LTS line and the weekly line, each as a WAR file, a Windows MSI, Linux packages and Docker images.

Is Jenkins free?

Yes. It is free and open source under the MIT licence, including for commercial use. You pay only for the servers and the people who run it.

What is the difference between Jenkins LTS and weekly?

The weekly line delivers new features and fixes about once a week. The LTS line takes a baseline every 12 weeks and then gets stable releases roughly every four weeks with bug and security fixes only. Production servers normally follow LTS.

Which Java version does Jenkins need?

The current installation documentation states Java 21 or later, and the LTS 2.580.x line is tested with JDK 21 and 25.

How do I install Jenkins on Windows?

Install Java, run the Jenkins MSI, choose a service account, open http://localhost:8080 and unlock it with the initialAdminPassword file. Then install plugins and create the administrator account.

What port does Jenkins use?

8080 by default. You can change it in the installer on Windows or with the JENKINS_PORT setting on Linux.

What is a Jenkinsfile?

A text file in the repository that describes a Pipeline: the stages, steps and conditions of a build. Because it is stored in Git, it is versioned and reviewed like any other code.

Last checked against official sources: 3 November 2026 (developer website: jenkins.io). Versions and licence terms change — confirm on the developer's site before deploying in production.