Validate.
Paste, upload, or write YAML. Validate against 11 configuration schemas, entirely in your browser.
What is YAML Validator?
A fast, browser-based online YAML validator for checking syntax and validating YAML files against schemas. Supports schema validation for Kubernetes, Docker Compose, GitHub Actions, and 8 more configuration formats. No server, no signup — all YAML validation happens locally in your browser.
11 Supported Schemas
YAML schema validation with auto-detection that identifies your YAML format from content patterns.
| Schema | Version | Auto-detection |
|---|---|---|
| Kubernetes | v1.29 | apiVersion + kind fields |
| Docker Compose | v2.29 | services + image/build |
| GitHub Actions | workflow | on + jobs fields |
| GitLab CI | latest | stages + script fields |
| CircleCI | v2.1 | version + jobs/workflows |
| Azure Pipelines | v1 | trigger + pool fields |
| Bitbucket Pipelines | pipes | pipelines field |
| Ansible | 2.x | hosts + tasks fields |
| Helm Chart | v2 | apiVersion + type chart |
| OpenAPI | 3.0 | openapi + paths fields |
| Swagger | 2.0 | swagger + paths fields |
Built for developers
Instant YAML Validation
Click validate or press Ctrl+Enter. Results in milliseconds, entirely client-side. Validate YAML files without sending data anywhere.
Schema Auto-Detection
Detects Kubernetes, Docker Compose, GitHub Actions, and more from content patterns. The YAML validator picks the right schema automatically.
Open & Save Files
Open YAML files from your computer, edit in-browser, and download when done. A complete online YAML file validator workflow.
Share via URL
Compressed sharing with no backend. Send YAML snippets to your team with a single link.
Multi-Document YAML
Full support for YAML files with multiple documents separated by ---. Validate all documents at once.
Dark & Light Themes
Easy on the eyes at any hour. The YAML validator remembers your theme preference.
Three steps
Paste or upload
Type YAML directly in the editor, paste from clipboard, or open a .yml file from your computer.
Pick a schema
Let auto-detection choose, or select from 11 built-in configuration schemas for YAML validation.
Validate & fix
See errors with line numbers and contextual hints. Fix issues and re-validate your YAML file until clean.
Questions
Is my YAML data sent to a server?
No. All parsing and validation happens entirely in your browser. Your data never leaves your machine.
What YAML versions are supported?
YAML 1.2 via js-yaml, with full support for anchors, aliases, multi-document files, and all standard data types.
Which schemas are supported for YAML validation?
11 built-in schemas: Kubernetes, Docker Compose, GitHub Actions, GitLab CI, CircleCI, Azure Pipelines, Bitbucket Pipelines, Ansible, Helm Chart, OpenAPI 3.0, and Swagger 2.0. Auto-detection identifies the right schema from your YAML content.
Is there a browser extension?
Yes. YAML Validator is available as a Chrome Extension and Firefox Add-on, adding validation, formatting, and code folding directly in your browser — including on GitHub YAML files.
Take it with you.
Validate YAML everywhere with the browser extension.