YAML Formatter & Converter

Client-Side New

Clean up messy YAML with consistent indentation, or convert between YAML and JSON formats instantly. The tool validates YAML syntax and provides clear error messages for common issues like bad indentation or invalid characters. Supports configurable indent sizes. All processing happens locally in your browser — no data leaves your machine.

Indent:

YAML Input

About YAML Formatter

Format — Clean up YAML with consistent indentation and structure
YAML → JSON — Convert YAML to JSON format for APIs or config files
JSON → YAML — Convert JSON to human-readable YAML format
All processing happens locally in your browser — nothing is sent to any server

How to Use

1

Choose a Mode

Select Format YAML to clean up indentation, YAML → JSON to convert to JSON, or JSON → YAML to convert from JSON.
2

Paste Your Content

Paste your YAML or JSON content into the input area. Choose your preferred indent size.
3

Process and Copy

Click the action button to format or convert. Copy the result or use it directly in your project.

Examples by Niche

Docker Compose

Format a messy docker-compose.yml with consistent 2-space indentation for clean version control diffs

CI/CD Pipelines

Convert a GitHub Actions workflow YAML to JSON to debug expression evaluation or validate structure

Kubernetes

Convert a JSON kubectl output to YAML format for use in Kubernetes manifest files

Frequently Asked Questions

Can this tool convert YAML to JSON?

Yes! The tool supports bidirectional conversion. You can convert YAML to JSON or JSON to YAML with a single click. The output preserves data types and nested structures.

Does this tool validate YAML syntax?

Yes, the tool validates YAML syntax using the js-yaml library. If your YAML has syntax errors like bad indentation or invalid characters, you'll see a clear error message pointing to the issue.

Is my YAML data safe?

Absolutely. All processing happens entirely in your browser. No data is ever sent to any server. Your YAML and JSON content stays on your machine.

What are common YAML syntax mistakes?

The most frequent YAML errors are incorrect indentation (YAML requires spaces, not tabs), missing colons after keys, unquoted strings that contain special characters like colons or hash symbols, and inconsistent indentation levels within a block. The validator will pinpoint the exact line where the error occurs.

What is YAML?

YAML is a human-readable data serialization format using indentation-based structure.

YAML vs JSON?

YAML is more human-readable with minimal syntax. JSON is stricter and machine-friendly.

Is YAML indentation-sensitive?

Yes. Indentation defines structure in YAML, making consistent spacing critical.

What is the YAML file extension?

Common extensions are .yaml and .yml. Both are accepted.

Can YAML include multiple documents?

Yes, use --- to separate multiple YAML documents in one file.

What is YAML used for?

Configuration files, CI/CD pipelines, Docker Compose, Kubernetes manifests, and Ansible playbooks.

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