How is this different from GitLab CI Lint?

CI Lint runs inside a project and needs access to it. YAMLTools works in any browser, without logging in, explains each problem and adds a risk report and a pipeline diagram.

Does it resolve include?

No: included files live in other repositories or URLs. They are recognised, and checks that depend on them are relaxed so you do not get false errors.

Can I see the pipeline as a diagram?

Yes. The Diagram tab draws stages, jobs and needs, so you can see the critical path of your pipeline.

Is my .gitlab-ci.yml uploaded?

No. Everything runs in your browser.

Does it support GitLab CI/CD components and inputs?

They are recognised as valid keys. Values that come from the component are not available offline, so they are not validated.

Free · no sign-up · in your browser

GitLab CI validator

Paste your .gitlab-ci.yml and check it without opening the project CI Lint: jobs, stages and dependencies, explained line by line.

GitLab CI

YAML

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Paste a file on the left to validate it.

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What YAMLTools checks in your GitLab CI file

The structure of each job: script, stage, needs, dependencies, rules and extends.
Jobs whose stage is not listed in stages.
needs and dependencies pointing to jobs that do not exist, and cycles.
rules mixed with only/except in the same job, which GitLab does not allow.
extends pointing to templates that are not defined, and extends cycles.

Risks it flags

Passwords and tokens in variables instead of masked CI/CD variables.
Images on :latest or without a tag.
Docker-in-Docker services and privileged runners.
Deploy jobs that run on every branch.
Scripts that download and execute remote code (curl | sh).

Common GitLab CI errors

The ones that break a deploy most often, and how YAMLTools reports them.

Stage not declared

stages: [test, build]
deploy:
  stage: release

GitLab refuses the pipeline: release is not in stages. YAMLTools marks the job and lists the valid stages.

needs to a missing job

needs: [test, lint]   # no lint job

The pipeline is not created. The report tells you which job name is missing.

rules together with only

rules:
  - if: $CI_COMMIT_BRANCH
only: [main]

GitLab does not allow both in the same job. Keep rules: only/except are deprecated.

Your file stays on your computer

Validation, risk analysis, diagram and conversions run in your browser. Nothing is uploaded unless you decide to save it with an account.

GitLab CI validator FAQ

Pipelines, includes and what happens with your file.