info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments
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description: "Learn how to use GitLab CI/CD, the GitLab built-in Continuous Integration, Continuous Deployment, and Continuous Delivery toolset to build, test, and deploy your application."
type: index
---
# GitLab CI/CD **(FREE)**
GitLab CI/CD is a tool built into GitLab for software development
through the [continuous methodologies](introduction/index.md):
- Continuous Integration (CI)
- Continuous Delivery (CD)
- Continuous Deployment (CD)
NOTE:
Out-of-the-box management systems can decrease hours spent on maintaining toolchains by 10% or more.
| [Custom path for `.gitlab-ci.yml`](pipelines/settings.md#specify-a-custom-cicd-configuration-file) | Define a custom path for the CI/CD configuration file. |
| [Integrate with Kubernetes clusters](../user/project/clusters/index.md) | Connect your project to Google Kubernetes Engine (GKE) or an existing Kubernetes cluster. |
| [Optimize GitLab and GitLab Runner for large repositories](large_repositories/index.md) | Recommended strategies for handling large repositories. |
| [Browser Performance Testing](../user/project/merge_requests/browser_performance_testing.md) | Quickly determine the browser performance impact of pending code changes. |
| [Load Performance Testing](../user/project/merge_requests/load_performance_testing.md) | Quickly determine the server performance impact of pending code changes. |
| [CI services](services/index.md) | Link Docker containers with your base image. |
| [Code Quality](../user/project/merge_requests/code_quality.md) | Analyze your source code quality. |
| [GitLab CI/CD for external repositories](ci_cd_for_external_repos/index.md) **(PREMIUM)** | Get the benefits of GitLab CI/CD combined with repositories in GitHub and Bitbucket Cloud. |
| [Interactive Web Terminals](interactive_web_terminal/index.md) **(FREE SELF)** | Open an interactive web terminal to debug the running jobs. |
| [Unit test reports](unit_test_reports.md) | Identify script failures directly on merge requests. |
| [Using Docker images](docker/using_docker_images.md) | Use GitLab and GitLab Runner with Docker to build and test applications. |
| [Canary Deployments](../user/project/canary_deployments.md) | Ship features to only a portion of your pods and let a percentage of your user base to visit the temporarily deployed feature. |
| [Deploy Boards](../user/project/deploy_boards.md) | Check the current health and status of each CI/CD environment running on Kubernetes. |
| [Feature Flags](../operations/feature_flags.md) **(PREMIUM)** | Deploy your features behind Feature Flags. |
| [Container Scanning](../user/application_security/container_scanning/index.md) **(ULTIMATE)** | Check your Docker containers for known vulnerabilities. |
| [Dependency Scanning](../user/application_security/dependency_scanning/index.md) **(ULTIMATE)** | Analyze your dependencies for known vulnerabilities. |
| [License Compliance](../user/compliance/license_compliance/index.md) **(ULTIMATE)** | Search your project dependencies for their licenses. |
| [Security Test reports](../user/application_security/index.md) **(ULTIMATE)** | Check for app vulnerabilities. |
## Examples
Find example project code and tutorials for using GitLab CI/CD with a variety of app frameworks, languages, and platforms
on the [CI Examples](examples/README.md) page.
## Administration **(FREE SELF)**
As a GitLab administrator, you can change the default behavior
of GitLab CI/CD for:
- An [entire GitLab instance](../user/admin_area/settings/continuous_integration.md).
- Specific projects, using [pipelines settings](pipelines/settings.md).
See also:
- [How to enable or disable GitLab CI/CD](enable_or_disable_ci.md).
- Other [CI administration settings](../administration/index.md#continuous-integration-settings).
## References
### Why GitLab CI/CD?
Learn more about:
- [Why you might choose GitLab CI/CD](https://about.gitlab.com/blog/2016/10/17/gitlab-ci-oohlala/).
- [Reasons you might migrate from another platform](https://about.gitlab.com/blog/2016/07/22/building-our-web-app-on-gitlab-ci/).
- [5 Teams that made the switch to GitLab CI/CD](https://about.gitlab.com/blog/2019/04/25/5-teams-that-made-the-switch-to-gitlab-ci-cd/)
See also the [Why CI/CD?](https://docs.google.com/presentation/d/1OGgk2Tcxbpl7DJaIOzCX4Vqg3dlwfELC3u2jEeCBbDk) presentation.
### Breaking changes
As GitLab CI/CD has evolved, certain breaking changes have
