The on key parsed incorrectly by YAML tooling
Some YAML parsers treat on as a boolean in older YAML modes. This tool uses YAML 1.2 behavior, and JSON output helps verify the parsed workflow keys.
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Validate Kubernetes, Docker Compose, and GitHub Actions YAML files with live syntax checking. Your YAML stays in your browser — no sign-up required.
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GitHub Actions workflow checker
GitHub Actions workflows combine YAML syntax, event triggers, jobs, steps, expressions, and secrets references. Use this page to catch YAML parser errors before pushing a broken file to .github/workflows.
Some YAML parsers treat on as a boolean in older YAML modes. This tool uses YAML 1.2 behavior, and JSON output helps verify the parsed workflow keys.
A misplaced run, uses, with, or env block can make a workflow fail before any job starts. Validate the file before pushing to avoid noisy CI failures.
Matrix jobs and reusable workflow inputs are often generated from templates. Paste generated YAML here to inspect arrays and nested objects in Tree View.
Paste or drag a workflow YAML file into the editor.
Validate syntax and resolve line/column errors before committing.
Use Tree View to inspect jobs, steps, matrices, env, and permissions.
Copy or download parsed output when reviewing generated workflow files.
No. It validates YAML syntax locally. GitHub still performs workflow-specific validation when the file is pushed.
Older YAML parsers may interpret on as a boolean. Inspecting parsed JSON helps confirm that the workflow trigger remains a string key.
The tool runs in your browser and does not upload content. Still, avoid pasting real secret values; use GitHub secrets references instead.
Quick answers to common questions.
Yes. All core features — validation, formatting, and conversion — are free to use without any sign-up or account required.