Jenkins vs. Circle CI

Jenkins and Circle CI serve as continuous integration (CI) tools that allow developers to integrate code branches during the development process and run a series of automated tests against them. They both transform the time?consuming, manual task of building, testing, and deploying software into a fast, automated process.

When comparing Travis CI with Jenkins, we need to consider our business needs and budget.

Jenkins

Jenkins is the most popular open-source automation server that was written in a java programming language. It facilitates the automation process of continuous integration and continuous delivery (CI/CD) in the software development process.

Jenkins supports over 1,400 plugins for other software tools. These plugins expand Jenkins into five years; platforms, UI, administration, source code management, and build management.

Jenkins is easy to install and use. It provides an impressive browser-hosted project management dashboard.

Some of the common reasons to evaluate and choose Jenkins include:

Open-source and free
Widely used and well documented
Vibrant user community
Integration with a large variety of tools and technologies.
Plugin support
Easy to install, configure and upgrade
Distributed builds
Monitoring external jobs
Support for various authentication methods, notification, version control system, etc.

Circle CI

Circle CI is a cloud-based tool that automates the integration and deployment process. It provides easy setup and maintenance without any difficulties. Circle CI is a cloud-based system, which means no dedicated server is required and no need for maintenance of server which has a free plan even for business accounts. It can be integrated with GitHub, Amazon EC2, dotCloud, Appfog, etc. and used by many companies such as Spotify, Facebook, RedBull, Harvest, and Teespring, etc.

Circle CI also focuses on testing every change to the code before it is deployed, using a number of methods such as unit tests, integrations tests, and functional tests. The tool supports containers, Linux, OSX, and can run within a private cloud or your own data center.

Circle CI comes with the following features:

Quick setup
Deep customization
Smart notifications
Automatic parallelization
It is easy and fast to start
Lightweight and easily readable YAML config
Don't need any dedicated server to run Circle CI.
It caches requirements installation and third-party dependencies instead of the installation of the environments.

Jenkins vs. Circle CI Comparison Table

The following are the primary comparisons between Jenkins and Circle CI:

Jenkins	Circle CI
In Jenkins, Builds are configured by Jenkins UI, and all settings of the jobs are stored on the Jenkins file system in Jenkins server which makes it hard to share configuration details with team or organization. By cloning Github or other source repositories can't copy information stored in Jenkins.	In CircleCI, we can construct all jobs within a single file called "circle.yaml". It is easy as CI configuration will be like any other source code repositories, which make it easy to share and backup. On CircleCI, only a small number of settings like secrets will be stored in an encrypted format.
In Jenkins, teams need to maintain the Jenkins server by installing all dependencies and debug if any issues are there.	In Circle CI, we don't need to maintain the server as every job will be started in a new environment where all the dependencies will be installed by default.
In Jenkins, debugging will be a little bit difficult.	In Circle CI, developers can debug easily using it's ssh feature.
The web UI of Jenkins is slow or less responsive due to more number of plugins.	The Web UI of Circle CI is frequently changing with improvements which make it popular among users.
In Jenkins, we don't have built-in support for Docker workflow, the user needs to install and make it available in the built environment.	In Circle CI, we have built-in support for Docker in workflow, which can be accessed by adding in services section in circle.yaml file.
Jenkins can support multiple jobs by multi-threading.	Circle CI has in-built support for parallelism, which can be achieved by project settings.
Jenkins environment will change only when the user instructs.	Circle CI changes environment without warning, which is an issue.
In Jenkins, secrets will be encrypted using Jenkins credentials and plugins.	In Circle CI, we don't have security like Jenkins.