YAML (YAML Ain't Markup Language) is a human-readable data serialization format used widely in configuration files, CI/CD pipelines (GitHub Actions, Docker Compose, Kubernetes), and APIs.

How does the formatter work?

The formatter normalizes indentation using your selected indent size (2 or 4 spaces), removes extra blank lines, and converts tabs to spaces. It preserves comments and values.

Can I convert YAML to JSON?

Yes. Use the 'Convert to JSON' mode to transform simple YAML structures into a JSON object. Works best with flat and singly-nested YAML.

Does this work with multi-line strings?

Yes, multi-line strings using | (literal block) and > (folded block) are preserved during formatting.

Is my YAML content sent anywhere?

No. All processing happens in your browser using JavaScript. Nothing is transmitted to any server.

What is YAML used for?

YAML is used for configuration files in Docker Compose (docker-compose.yml), Kubernetes manifests, GitHub Actions workflows, Ansible playbooks, and many other DevOps and development tools.

What is the difference between YAML and JSON?

YAML is a superset of JSON that is more human-readable, supports comments, and uses indentation instead of braces. JSON is stricter and better for machine-to-machine communication. Most YAML can be converted to equivalent JSON.

Does the formatter validate YAML syntax?

The formatter performs basic structural normalization. Full YAML validation (including complex anchors, aliases, and multi-document streams) requires a full parser library.

YAML Formatter & Validator — Format YAML Online Free

Format and beautify YAML configuration files online. Normalize indentation, convert YAML to JSON. Supports 2 and 4-space indent. Free, no upload required.

Indent:

YAML Input

Formatted YAML

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What is YAML Formatter & Validator — Format YAML Online Free?

YAML (YAML Ain't Markup Language) is a human-readable data serialization format widely used for configuration files in tools like Docker Compose, Kubernetes, GitHub Actions, Ansible, and more. Our YAML Formatter normalizes indentation, cleans up extra blank lines, and preserves comments. It also includes a YAML to JSON converter for quick interoperability.

How to Use YAML Formatter & Validator — Format YAML Online Free

1Paste your YAML content into the input area on the left.
2Select 'Format YAML' to normalize indentation, or 'Convert to JSON' to convert to JSON.
3Choose your preferred indent size (2 or 4 spaces).
4Copy the formatted output using the Copy button or clear to start over.

Key Features

Normalize YAML indentation (2 or 4 spaces)
Tab-to-space conversion
Remove excessive blank lines
Convert YAML to JSON
Preserve comments
Runs entirely in your browser

Benefits

Fix malformed YAML configuration files quickly
Standardize indentation across team YAML files
Convert YAML config to JSON for API use
Validate YAML syntax before deploying

Use Cases

Format without software

Why Use Irreva for YAML Formatter & Validator — Format YAML Online Free?

Fix malformed YAML configuration files quickly

Standardize indentation across team YAML files

Convert YAML config to JSON for API use

Runs 100% in your browser — files never leave your device.

No account, no sign-up, no subscription — free forever.

Works on any device: desktop, tablet, or mobile.

Frequently Asked Questions

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