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DEVELOPER TOOLS

JSON, YAML & XML Formatter

Validate syntax with line and column error indicators, format with custom indent (2, 4 spaces or tab), or minify JSON and XML. Convert between JSON and YAML without uploading data.

Tool statusRuns in your browser
Preview
prontouso://dev/data-formatter
LocalJSON · YAML · XML

Choose an input format to see what this mode does for it.

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Validation

Before transformation
Paste a document to begin

The tool identifies the format and reports errors before producing a result.

Document

Summary
—Format
—Main type
—Keys / nodes
—Size change

How it works

  1. Enter your input

    Fill in the values, paste your text, or upload the file this tool works with.

  2. See results instantly

    Most tools update live as you type; a few use a single button. Either way, the result appears right on this page.

  3. Use your results

    Copy, download, or share what the tool produces — you're always in control of the output.

Privacy and processing — Runs locally in your browser. This tool does not upload your input.

What is JSON, YAML & XML Formatter?

The JSON, YAML & XML Formatter lets you organize, validate, and minify structured files with custom 2-space, 4-space, or tab indentation, as well as convert data between JSON and YAML in real time.

UNDERSTAND THE TOOL

How to format, validate, and convert JSON, YAML, and XML files

Learn how to adjust indentation, locate syntax errors by line and column, minify payloads, and safely convert data structures between JSON and YAML.

JSON formatting and minification

Formatting restructures JSON with configurable indentation (2 spaces, 4 spaces, or tabs), making nested objects and arrays easy to inspect. Minifying removes unnecessary line breaks and whitespace, reducing payload size for APIs and database storage without modifying any underlying data values.

Real-time syntax diagnostic and validation

The tool parses document syntax instantly and reports the exact line and column when an error occurs. In JSON, frequent syntax issues include using single quotes instead of double quotes, trailing commas before closing braces or brackets, and missing quotes around property keys.

Bidirectional JSON and YAML conversion

You can convert JSON objects into clean YAML structures and turn YAML documents back into formatted JSON. The conversion preserves primitive data types (numbers, booleans, nulls, and strings) using standard JSON-compatible schemas for interoperability.

XML document formatting and tag handling

For XML, the engine arranges parent and child tags into a clear hierarchy, normalizes self-closing tags (<item/>), preserves XML declarations, comments, and CDATA blocks, and respects xml:space="preserve" attributes so that whitespace-sensitive text remains intact.

Practical conversion and minification example

Converting a JSON object to YAML and compact format

See how a JSON configuration converts to clean YAML syntax and a compact single-line minified string for network requests:

{"service": "api", "ports": [80, 443]} -> service: "api"\nports:\n - 80\n - 443

100% local browser processing

All syntax validation, formatting, and file conversions (JSON, YAML, YML, XML, TXT) run in browser memory via JavaScript. No structured payloads or file contents are ever uploaded to external servers.

Frequently Asked Questions

What is the difference between beautifying (formatting) and minifying?

Formatting adds line breaks and hierarchical indents to improve human readability. Minifying strips all unnecessary whitespace and line breaks to minimize file size for network transfer and storage.

Why does the validator report an error in my JSON when it looks correct?

JSON syntax is strictly enforced: keys and string values must use double quotes (single quotes are invalid), trailing commas before closing braces or brackets are forbidden, and comments are not allowed.

Does YAML to JSON conversion preserve all data types?

Yes. Mappings, sequences, numbers, booleans, nulls, and strings are faithfully converted between JSON and YAML specifications using standard compatible schemas.

How does the formatter handle XML attributes and CDATA blocks?

Tags and attributes are formatted into a tree hierarchy, empty elements become self-closing, and CDATA sections or nodes with xml:space="preserve" retain their exact raw content without artificial line breaks.

Does this tool validate against a custom JSON Schema?

This tool focuses on grammar and syntactic structure validation. To validate business rules against a schema contract, use a dedicated JSON Schema validator.

Is there a file size limit for formatting?

You can paste or upload text files up to 2 MB directly in your browser, ensuring fast client-side performance without interface lag.

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