CircleCI vs. GitHub Actions: CI/CD platform comparison

Learn the differing features, commands and perks that make CircleCI and GitHub Actions distinct CI/CD platforms. Then, decide which offering meets your team's needs.

The right CI/CD platform can make or break an organization's application development efforts. While CI/CD platforms and tools serve the same general purpose, success hinges on an IT organization's programmers and their specific development processes.

Two prominent CI/CD platforms to consider are CircleCI and GitHub Actions. Each tool has its own respective features, processes and pipeline workflows that appeal to programmers.

Also, each offers both a free and paid tier. The free tiers come with features such as on-demand compute instances to build, test and deploy your application; a configuration file written in YAML to define CI/CD processes; a convenient dashboard to monitor project build status and other functionalities.

Let's compare CircleCI vs. GitHub Actions for CI/CD platform options and examine which features development teams should look for.

CircleCI vs. GitHub Actions feature breakdown

Both CircleCI and GitHub Actions are available as a self-hosted platform or as a SaaS product.

Repository compatibility. When using the SaaS option, a programming team's repository needs continual access to the platform to retrieve the application source code. CircleCI works with public or private repositories stored in GitHub or Bitbucket. Comparatively, GitHub Actions is available only for repositories stored in GitHub. Before finalizing a decision on CircleCI vs. GitHub Actions, team members will need to confirm that their repositories are supported by their preferred platform.

CircleCI works with public or private repositories stored in GitHub or Bitbucket. Comparatively, GitHub Actions is available only for repositories stored in GitHub.

User interfaces. Some IT organizations prefer GitHub Actions because it's more tightly integrated with their code repositories on GitHub. Development teams will like the familiar UI. If a team's repositories aren't linked to GitHub, CircleCI has UI features that could prove to be beneficial. For a team that wants to house an application's pipeline and code repository in the same place, GitHub Actions could have the edge.

Amount of compute time. Public repository users will have free and unlimited compute times on GitHub Actions. However, private repository users of GitHub Action's free tier are limited to 2,000 minutes of compute time per month.

CircleCI's free tier offers 30,000 credits -- how CircleCI measures users and compute instance usage per build -- each month for both private and public repositories. For example, the 30,000 credits in the free tier would provide 3,000 build minutes when using a Docker or Linux medium compute instance at 10 credits per minute. Here's another way to frame this:

  • GitHub Actions' free tier has unlimited minutes for public repos.
  • GitHub Actions' free tier has a limit of 2,000 minutes for private repos.
  • CircleCI's free tier has no differentiation between public and private repos.
  • CircleCI's free tier generally offers 3,000 minutes.
GitHub Actions is more cost-effective for users of public repositories. However, CircleCI can offer a better deal for projects with private repositories.

When teams compare the two platforms, they'll find that GitHub Actions is more cost-effective for users of public repositories. However, CircleCI can offer a better deal for projects with private repositories.

Paid versions. A team that opts for the paid tier of CircleCI will benefit from larger compute instance sizes and more credits per month. These functionalities allow programmers to run more builds with extra credits and run builds quicker with more compute power. The paid tiers in CircleCI also allow more users, which applies to private repositories. On GitHub Actions, the paid tiers unlock more minutes of build time. The vendor breaks down the features available in the Free, Team and Enterprise versions here.

Compute specifications options. CircleCI allows builds to be run on different compute instances. For certain projects, it may make sense to use a larger instance size to improve build times at the cost of spending more credits. However, GitHub Actions only offers the ability to run on a Windows, MacOS or Linux machine with particular, unmodifiable specifications.

File separation. While CircleCI forces pipelines to exist as a singular configuration YAML file, GitHub Actions pipelines can be broken into separate YAML files for each workflow. For example, programmers in GitHub Actions can create multiple YAML files; a team may split up the files based on the environment for which a team has tested and built an application. This feature can help developers create a cleaner design for applications that use a different build process for a development and production environment.

Build access. CircleCI offers SSH access to builds while GitHub Actions does not. With SSH access, programmers will find it easy to debug issues with nonpresent commands or files in unexpected directories.

Orbs vs. Actions

Both CI/CD platforms offer a reusable, simplified command that enables a pipeline to pull in predefined, commonly used processes. In GitHub Actions, the feature is called Actions. The CircleCI counterpart is called orbs. With this feature, development teams can save time and limit process complexity.

Design differences. Many orbs -- i.e., commands -- exist for often-used services from cloud providers, such as AWS, Azure and Google Cloud Platform. For example, programmers can use a CircleCI orb to call a command like aws-ecr/build-and-push-image.

With this orb, CircleCI will build a Docker image and automatically push it up to the desired ECR repository. For sensitive internal processes, programmers can create private orbs only available to their IT organization.

GitHub Actions are similarly supported by cloud providers, but don't offer an option to publish an Action privately. For example, building and pushing up an image on ECR with GitHub Actions looks like this:

- name: Login to Amazon ECR

id: login-ecr
uses: aws-actions/amazon-ecr-login@v1
- name: Build, tag, and push image to Amazon ECR
ECR_REGISTRY: ${{ steps.login-ecr.outputs.registry }}
ECR_REPOSITORY: my-ecr-repo
IMAGE_TAG: ${{ github.sha }}
run: |

Whereas, the equivalent operation using CircleCI's orbs looks like this:

- aws-ecr/build-and-push-image:
account-url: AWS_ECR_ACCOUNT_URL
region: AWS_REGION
repo: '${MY_APP_PREFIX}'
tag: '${CIRCLE_SHA1}'

When programmers use CircleCI, they'll likely discover that the platform provides the parameters to form an operation and the orb can handle the rest. Contrastingly, GitHub Actions requires more input and specifically requires the Docker commands. CircleCI's design could be considered cleaner and simpler, while GitHub Actions offers more granular control by exposing commands that CircleCI keeps behind the curtain.

Final considerations for CircleCI vs. GitHub Actions

While CircleCI and GitHub Actions accomplish the same tasks, each service has a different feel and ethos.

Teams may feel compelled to use one platform over the other based on their repository selection and perceived process compatibility. If teams can, they should try each service so programmers can evaluate each option and best determine which tool is the best fit for their organization's build and test processes.

Next Steps

CI/CD tutorial: How to set up a pipeline

Automate workflows by running PowerShell in GitHub Actions

Dig Deeper on Software development lifecycle

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