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HomeConvertersYAML Formatter — Validate, Format & Convert Online
Converters

YAML Formatter — Validate, Format & Convert Online

Browser-Only

Validate YAML syntax, format with block or flow style, and convert between YAML and JSON. Key counts, structure preview, and shareable settings — free and private.

ValidateFormatConvertFree

How to Use

Step-by-step guide to get the most from this tool

  1. 1

    Choose mode

    Select Validate, Format YAML, or Convert between YAML and JSON.

  2. 2

    Paste input

    Enter your YAML or JSON in the input panel.

  3. 3

    Adjust options

    Set indent (2 or 4) and block/flow style where applicable.

  4. 4

    Copy output

    Copy the formatted or converted result, or share your settings via link.

Features

What makes this tool stand out

✓

Validate

Syntax errors with line and column numbers.

📐

Format

Normalize indentation with block or flow style.

↔️

Convert

Bidirectional YAML ↔ JSON conversion.

🔒

Private

100% client-side — configs never uploaded.

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📋
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Frequently Asked Questions

Quick answers to common questions

How do I validate YAML?+

Select Validate mode and paste your YAML. Valid files show a success message with key count. Syntax errors display the parser line and column.

What is block vs flow YAML style?+

Block style uses indented nested structures (default for configs). Flow style uses inline JSON-like notation for compact output.

How do I convert YAML to JSON?+

Select Convert mode with YAML → JSON, paste your YAML, and copy the formatted JSON output.

Can I convert JSON to YAML?+

Yes. Switch to JSON → YAML in Convert mode, paste JSON, and get formatted YAML with your chosen indent and style.

Is my data uploaded to a server?+

No. All parsing and conversion happens entirely in your browser. Your configs never leave your device.

What YAML features are supported?+

Standard YAML 1.2 including arrays, nested objects, booleans, and numbers. Kubernetes and Docker Compose configs are supported.

What indent size should I use?+

Most projects use 2 spaces. You can also choose 4 spaces for both YAML formatting and JSON output.

YAML vs JSON — when to use which?+

YAML is human-readable for config files (Kubernetes, CI/CD). JSON is better for APIs and data interchange.

Your data is processed entirely in your browser. Nothing is sent to any server.