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CircleCI

CircleCI

Cloud and self-hosted CI/CD with a strong reputation for fast pipelines and config-as-code. Native AI features: AI Test Insights for flaky test detection, ML-driven test splitting, and pipeline anomaly detection. Resource classes from small to GPU. Integrates with every major SCM and cloud, with first-class macOS for iOS builds.

Last reviewedMay 15, 2026
How we review

Overview

CircleCI is a container-native CI platform. Pipelines are defined in .circleci/config.yml using a YAML model that distinguishes jobs (units of work), steps (commands within a job), and executors (compute environment: Docker, machine, macOS, Windows, GPU). Jobs within a workflow run in parallel or in dependency order.

Orbs are reusable, versioned packages of CircleCI configuration that encapsulate jobs, commands, and executors, distributed via the Orb Registry. Docker Layer Caching stores intermediate image layers between runs. Test splitting distributes test files across parallel containers based on historical run-time data so all containers complete at approximately the same time.

Resource classes configure compute per job (CPU, memory, OS), enabling jobs with different compute requirements to run on appropriately sized machines within the same workflow. A self-hosted runner option and an on-premises server product cover isolated environments. Pricing is credit-based; credits are consumed at different rates per resource class. Free tier: 6,000 credits/month on Linux.

Key Features

  • Orbs: reusable, versioned, composable config packages that encapsulate jobs, commands, and executors — stronger typing and composability than GitHub Actions' marketplace model for complex pipeline logic
  • Docker Layer Caching (DLC): caches intermediate Docker image layers between pipeline runs, reducing build times on image-heavy workflows without storing full images in an external registry
  • Test splitting: automatically distributes test files across parallel containers based on historical timing data, balancing workload so all containers finish at approximately the same time
  • Resource classes: configurable compute per job (Docker, machine, macOS, Windows, GPU) with memory and CPU sizing — jobs with different compute needs run on appropriate hardware within the same workflow
  • Pipeline config splitting for monorepos: dynamic config generation allows large repositories to only run the pipelines relevant to changed paths, avoiding full-suite runs on unrelated changes
  • Insights: per-workflow and per-job analytics showing build duration trends, flaky test rates, and credit consumption — surfaces which jobs are the slowest and most expensive across the pipeline

Integrations

8 total
scm
GitHubGitLabBitbucket
ci / cd
Terraform
cloud
AWSGCP
orchestration
Kubernetes
messaging
Slack

Pricing

No pricing data on file.

Compare with similar tools

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Compliance

2 / 6 attested
SOC 2
HIPAA
GDPR
FedRAMP
PCI DSS
ISO 27001

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