GitHub Actions vs CircleCI

Overview

What are the key differences between GitHub Actions and CircleCI?

GitHub Actions and CircleCI differ in pricing model, config structure, executor types, and reuse ecosystems. This table compares the dimensions that affect cost and developer experience.

Pricing

How does GitHub Actions pricing compare to CircleCI?

On standard Linux 2-vCPU runners, GitHub Actions and CircleCI cost the same: $0.006 per minute. The two platforms bill differently — GitHub Actions charges per minute of runner time, while CircleCI uses an intermediary currency called credits. Each resource class consumes credits at a different rate per minute, and credits cost $0.0006 each (or $15 per 25,000).

GitHub Actions includes 2,000 free minutes/month on Free, 3,000 on Team/Pro, and 50,000 on Enterprise. Overage on the standard Linux 2-core runner is $0.006/min. Windows costs $0.010/min and macOS costs $0.062/min. GitHub rounds each job up to the nearest whole minute.

CircleCI gives Free plans 30,000 credits/month (~3,000 minutes on Linux medium Docker). The Performance plan starts at $15/month and charges $15 per additional 25,000 credits. On Docker medium (2 vCPU, 4 GB), that works out to $0.006/min, identical to GitHub's Linux rate. But CircleCI's machine VMs (which give you a full VM like GitHub's runners) cost more: Linux machine medium also runs 10 credits/min, but larger machine classes jump sharply (100 credits/min for 8 vCPU vs 40 for Docker xlarge with the same 8 vCPU).

On the standard Linux Docker executor at 2 vCPU, the per-minute cost is identical: $0.006/min on both platforms. At this workload (50 builds/day, 8 min each), both platforms charge about $35/mo in overage. The difference is in the base plan cost: GitHub Team is $4/user/month, while CircleCI Performance starts at $15/month plus $15/user/month in credits for active users beyond the first five.

The cost gap widens on larger runners and non-Linux executors. CircleCI's macOS M4 Pro medium costs 200 credits/min ($0.12/min), roughly double GitHub's $0.062/min for macOS. Windows is also more expensive on CircleCI: 40 credits/min ($0.024/min) vs GitHub's $0.010/min. If your team runs iOS or Windows builds frequently, the pricing difference is significant.

Configuration

How does GitHub Actions config differ from CircleCI?

GitHub Actions stores workflows in multiple .github/workflows/*.yml files with a workflow → jobs → steps hierarchy. CircleCI uses a single .circleci/config.yml where jobs are defined separately, then composed into workflows with dependency ordering via requires:.

Here is the same pipeline (lint, test, build) on each platform:

name: CI
on:
  push:
    branches: [main]
  pull_request:

jobs:
  lint:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: 20
      - run: npm ci
      - run: npm run lint

  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: 20
      - run: npm ci
      - run: npm test

  build:
    needs: [lint, test]
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - run: npm run build

version: 2.1

jobs:
  lint:
    docker:
      - image: cimg/node:20.0
    steps:
      - checkout
      - run: npm ci
      - run: npm run lint

  test:
    docker:
      - image: cimg/node:20.0
    steps:
      - checkout
      - run: npm ci
      - run: npm test

  build:
    docker:
      - image: cimg/node:20.0
    steps:
      - checkout
      - run: npm run build

workflows:
  ci:
    jobs:
      - lint
      - test
      - build:
          requires:
            - lint
            - test

The structural difference: GitHub Actions defines everything inside a single workflow file. Triggers, jobs, and steps all live together. CircleCI separates job definitions from workflow orchestration. You define jobs at the top level, then wire them into one or more workflows: blocks with dependency ordering. This separation means you can reuse the same job definition across multiple workflows without duplication.

Another key difference: GitHub Actions gives each job a full VM (specified with runs-on:). CircleCI's default is a Docker container (specified with docker:), which starts faster but does not support Docker-in-Docker without the setup_remote_docker step. For workloads that need a full VM (Docker builds, privileged operations), CircleCI offers the machine: executor.

Runners

How do GitHub Actions runners compare to CircleCI executors?

GitHub Actions runners and CircleCI executors (resource classes) are priced similarly for Linux but diverge on macOS, Windows, and Arm. GitHub Actions provides more RAM per vCPU (7 GB vs 4 GB at 2 vCPU) and is cheaper for non-Linux workloads.

For Linux Docker workloads at small and medium sizes, the per-minute cost is nearly identical. GitHub's advantage shows at larger sizes, macOS, and Windows, where CircleCI's rates are higher. One caveat: CircleCI's Docker executor gives you less RAM per vCPU than GitHub's VM runners (4 GB vs 7 GB at 2 vCPU). If your builds are memory-hungry, you may need a larger CircleCI resource class, increasing effective cost.

CircleCI also offers a wider range of executor types. Beyond Docker and machine VMs, there are GPU resource classes (Nvidia P4, T4, A10G, V100) available on Performance and Scale plans. GitHub Actions added GPU runners (4-core with Nvidia) at $0.052/min for Linux, compared to CircleCI's starting at $0.096/min (160 credits/min) for the small GPU class.

Caching

How does caching differ between GitHub Actions and CircleCI?

GitHub Actions caches via the actions/cache marketplace action with a 10 GB per-repo limit. CircleCI uses built-in restore_cache and save_cache steps with immutable cache keys and plan-based storage limits.

steps:
  - uses: actions/checkout@v4
  - uses: actions/cache@v4
    with:
      path: ~/.npm
      key: npm-${{ hashFiles('**/package-lock.json') }}
      restore-keys: npm-
  - run: npm ci

steps:
  - checkout
  - restore_cache:
      keys:
        - npm-{{ checksum "package-lock.json" }}
        - npm-
  - run: npm ci
  - save_cache:
      key: npm-{{ checksum "package-lock.json" }}
      paths:
        - ~/.npm

GitHub Actions uses the actions/cache action with a 10 GB per-repository limit. Caches are stored in Azure Blob Storage, scoped to the repository, and evicted after 7 days of no access. The restore and save happen as a single action.

CircleCI splits caching into two explicit steps: restore_cache and save_cache. This gives you precise control over when caches are saved (e.g., only after a successful install). CircleCI caches are immutable: once a key is written, it cannot be overwritten. If your lockfile changes, a new cache entry is created. Old entries are evicted based on plan storage limits (2 GB on Free, more on paid plans). Network egress for cache downloads is metered at 420 credits/GB on paid plans.

Ecosystem

What are CircleCI orbs and how do they compare to GitHub Actions?

CircleCI orbs are reusable YAML packages that can define commands, jobs, and executors. GitHub Actions uses marketplace actions — Docker containers or JavaScript that run as individual steps. GitHub's marketplace has over 21,000 actions, while CircleCI's orb registry is smaller but more structured.

steps:
  - uses: actions/checkout@v4
  - uses: aws-actions/configure-aws-credentials@v4
    with:
      role-to-assume: arn:aws:iam::role/deploy
      aws-region: us-east-1
  - run: aws s3 sync ./dist s3://my-bucket

version: 2.1

orbs:
  aws-cli: circleci/aws-cli@5.1

jobs:
  deploy:
    docker:
      - image: cimg/base:current
    steps:
      - checkout
      - aws-cli/setup
      - run: aws s3 sync ./dist s3://my-bucket

GitHub's Actions Marketplace has over 21,000 community actions. You reference them with uses: owner/action@version. Actions are Docker containers or JavaScript that run as steps in your workflow. The selection is massive, but you are running third-party code in your CI environment.

CircleCI's equivalent is orbs: reusable YAML packages that can define commands, jobs, and executors. Orbs are more structured than GitHub Actions. They can expose parameterized commands (reusable step sequences) and full job definitions, not just individual steps. The orb registry is smaller than GitHub's marketplace but covers most common integrations (AWS, GCP, Slack, Docker, Node, Python). Organizations can also publish private orbs for internal reuse.

Test splitting

Does CircleCI or GitHub Actions have better test splitting?

CircleCI has built-in test splitting with parallelism that GitHub Actions does not offer natively. You set parallelism: N on a job, and CircleCI automatically spins up N containers and distributes test files across them using timing data from previous runs. GitHub Actions requires manual sharding via matrix builds.

# Manual sharding via matrix
test:
  strategy:
    matrix:
      shard: [1, 2, 3, 4]
  runs-on: ubuntu-latest
  steps:
    - uses: actions/checkout@v4
    - run: npm ci
    - run: |
        npx jest --shard=${{ matrix.shard }}/4

# Built-in parallelism with timing split
test:
  docker:
    - image: cimg/node:20.0
  parallelism: 4
  steps:
    - checkout
    - run: npm ci
    - run: |
        TEST_FILES=$(circleci tests glob \
          "src/**/*.test.ts" | \
          circleci tests split --split-by=timings)
        npx jest $TEST_FILES

CircleCI's circleci tests split --split-by=timings uses historical timing data to distribute tests evenly across containers, minimizing wall-clock time. On GitHub Actions, you need to manually implement sharding using matrix builds and either a framework-level shard flag (like Jest's --shard) or a third-party action. GitHub does not provide timing-based splitting natively.

One caveat: parallelism increases your total credit consumption. Four parallel containers running for 3 minutes each costs the same as one container running for 12 minutes. The benefit is reduced wall-clock time (faster feedback), not reduced cost. See our over-parallelized test suites guide for when this tradeoff stops making sense.

Decision framework

When should you choose GitHub Actions over CircleCI?

• Your code is on GitHub. PR checks, branch protection, status checks, deployments, and environments all integrate without configuration. No OAuth apps or webhooks to set up. CircleCI requires connecting to GitHub as an external service.

• You run macOS or Windows builds. GitHub's macOS rate ($0.062/min) is roughly half CircleCI's M4 Pro rate ($0.120/min). Windows is $0.010/min vs $0.024/min. For teams with significant non-Linux workloads, this gap adds up.

• You want fewer vendors. GitHub Actions eliminates a separate CI vendor relationship, one fewer login, one fewer billing line item, one fewer support channel. For small teams, this consolidation matters.

• You run open-source projects. GitHub Actions is free for public repos with no minute limits. CircleCI offers 400,000 credits/month for open-source Linux builds, which is generous but still metered.

Decision framework

When should you choose CircleCI over GitHub Actions?

• You need native test splitting. CircleCI's parallelism + circleci tests split --split-by=timings is the best built-in test distribution in any hosted CI platform. If your test suite takes 20+ minutes and you want to shard it across containers without building custom tooling, CircleCI handles it.

• You prefer Docker-first workflows. CircleCI's Docker executor is a first-class citizen. Jobs start in a container you specify, with no VM overhead. You can attach multiple service containers (databases, caches) to a single job using the docker: key. GitHub Actions requires you to run services as Docker containers via a separate services: block, which is less ergonomic for complex stacks.

• You want more granular resource classes. CircleCI offers resource classes from 1 vCPU (small, 5 credits/min) up to 32 vCPU, including intermediate sizes like medium+ (3 vCPU) that do not exist in GitHub Actions. If your workload is CPU-bound but does not need 4 cores, the 3-vCPU option lets you right-size more precisely.

• You use multiple VCS providers. CircleCI supports GitHub, GitLab, and Bitbucket as source code providers. If your organization has repositories across multiple Git hosts, CircleCI can serve as a single CI platform for all of them. GitHub Actions only works with GitHub repositories.

Migration

What are the challenges of migrating between GitHub Actions and CircleCI?

Migrating between GitHub Actions and CircleCI requires rewriting configs, not translating them. The pipeline models, executor types, and reuse mechanisms are different enough that direct YAML conversion does not work. Here are the primary friction points:

• Orbs have no direct GitHub equivalent. If your CircleCI config uses orbs heavily, each orb needs to be replaced with an equivalent marketplace action or raw script steps. The circleci/node orb maps roughly to actions/setup-node, but orbs that define entire jobs (not just steps) require more restructuring.

• Workflow orchestration syntax differs. CircleCI's requires: maps to GitHub's needs:, but CircleCI's filter-based branch targeting (filters: branches: only: [main]) has no direct equivalent. In GitHub Actions, branch filtering happens at the trigger level (on: push: branches:), not at the job level.

• Docker executor does not exist in GitHub. If you rely on CircleCI's Docker executor for fast container startups and multi-image service stacks, GitHub's VM-based model will feel different. You can use services: in GitHub Actions for sidecar containers, but the primary job always runs in a VM.

• Secrets and contexts. CircleCI uses contexts to group environment variables and share them across projects. GitHub uses repository, environment, and organization-level secrets. You will need to re-create every variable in the target platform. Neither platform supports export/import of secrets.

GitHub provides an official migration guide from CircleCI to GitHub Actions that covers the major syntax mappings. CircleCI documents how their concepts map to GitHub in their GitHub Actions migration reference.