How to use YAML Formatter & Validator
Paste your input on the left, choose the options you want, and the output appears instantly on the right. Everything runs in your browser — none of your data is sent to a server.
- Paste or type your input in the
INPUTpanel - The output regenerates automatically as you type
- Use
Copyto put the result in your clipboard - Click
Sampleto load a working example
What is YAML Formatter & Validator?
YAML (YAML Ain't Markup Language) is a human-readable data serialization format widely used for configuration files (Kubernetes, GitHub Actions, Docker Compose). This tool formats your YAML, validates syntax, and can convert it to JSON for use in APIs or scripts. All processing happens in your browser — your data stays private. This tool is part of santekno's developer toolbox — a curated collection of utilities built for engineers who care about speed, privacy, and simplicity.
Common use cases
- Debugging API payloads and integration issues
- Inspecting tokens, hashes, or encoded strings during development
- Generating fixtures and sample data for tests
- Sharing readable output with teammates in code reviews
FAQ
YAML is commonly used for configuration files in DevOps tools like Kubernetes, GitHub Actions, Docker Compose, and Ansible. It is more readable than JSON for human editing.
Yes — toggle the "Convert to JSON" option to get JSON output instead of formatted YAML.
Common issues: inconsistent indentation (mix of tabs and spaces), missing colons, or duplicate keys. The error message shows the line and column where parsing failed.
Yes, this tool uses js-yaml which supports YAML 1.2 specification including merge keys, anchors, and aliases.
No. All parsing and formatting happens entirely in your browser. Nothing is uploaded.