JSON to YAML Converter
Convert JSON to YAML and YAML back to JSON. Preserve YAML comments, customize indentation, and control output formatting.
About JSON to YAML Converter
Our free online JSON to YAML Converter is a powerful bidirectional utility that transforms JSON data into clean, readable YAML format and vice versa. This tool is essential for developers working with configuration files, DevOps pipelines, API integrations, and any scenario where data needs to be converted between these two popular formats.
The JSON to YAML conversion handles all JSON data types including objects, arrays, strings, numbers, booleans, and null values. YAML's more concise syntax often results in smaller file sizes compared to JSON, especially for deeply nested structures. The converter supports customizable indentation (2 or 4 spaces), line width limits for readability, and options to control alias usage and string quoting behavior.
The YAML to JSON conversion parses YAML 1.2 documents and reconstructs valid JSON output. A key feature is comment preservation: when converting YAML to JSON, all YAML comments (lines starting with #) are extracted and displayed in a dedicated comments panel. When converting back to YAML, these comments can be re-inserted at their original positions or added as block comments above their associated keys. This makes the tool ideal for editing configuration files while preserving developer documentation.
All processing happens directly in your browser using the js-yaml library, so your data never leaves your device. This ensures complete privacy and security for your sensitive configuration files, API keys, and deployment settings.
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Features
Bidirectional Conversion
Convert JSON to YAML and YAML back to JSON with a single click. Perfect for configuration and data transformation workflows.
Comment Preservation
Extract and display YAML comments during conversion. Re-insert comments when converting back to YAML.
Custom Indentation
Choose 2 or 4 space indentation for YAML output. Configure line width for optimal readability.
Quote Control
Optionally force quotes on all string values in YAML output for stricter formatting requirements.
Alias Handling
Control YAML anchor and alias generation. Disable aliases for simpler output when needed.
Copy & Download
One-click copy to clipboard or download the converted data as a file (.json or .yaml).
Auto-Convert
Enable auto-convert mode to transform your data automatically as you type in real-time.
Statistics
View input/output character counts, comment count, and line count for quick data overview.
Privacy First
All conversion happens in your browser. Your data never leaves your device, ensuring complete security.
How to Use
Paste Your Data
Paste JSON or YAML data into the left input editor. Click "Sample JSON" or "Sample YAML" to load example data.
Configure Options
Set indentation, line width, alias behavior, quote preferences, and comment style for the conversion.
Convert
Click "JSON to YAML" or "YAML to JSON" to perform the conversion. The result appears in the right output editor.
Copy or Download
Click Copy to copy the converted data to clipboard, or Download to save it as a file (.json or .yaml).
Frequently Asked Questions
What is the difference between JSON and YAML?
JSON (JavaScript Object Notation) and YAML (YAML Ain't Markup Language) are both data serialization formats. YAML is a superset of JSON and is generally more human-readable. Key differences: YAML uses indentation instead of braces, doesn't require quotes around strings, supports comments, and has a more concise syntax. JSON is stricter but more universally supported in web APIs. YAML files are typically 20-40% smaller than equivalent JSON files.
How are YAML comments preserved?
When converting YAML to JSON, all comments (lines starting with #) are extracted and displayed in a dedicated "Extracted YAML Comments" panel below the editors. The comments are stored with their line numbers and associated keys. When converting JSON back to YAML, you can choose to re-insert these comments as inline comments (after the value) or block comments (on a line above the key). This preserves documentation and notes during format conversion.
What YAML version is supported?
This tool supports YAML 1.2, the latest version of the YAML specification. YAML 1.2 is a strict superset of JSON, meaning any valid JSON is also valid YAML. The tool uses the js-yaml library for parsing and serialization, which fully implements the YAML 1.2 spec with support for all standard YAML types, anchors, aliases, and multi-document streams.
How are YAML anchors and aliases handled?
By default, the converter disables YAML aliases (anchors and references) for simpler output. You can enable aliases by unchecking the "No aliases" option. When enabled, duplicate objects or arrays in the JSON will be represented using YAML anchors (&name) and aliases (*name) to reduce file size and improve readability.
Can this tool handle multi-document YAML files?
The current implementation handles single YAML documents. Multi-document YAML files (separated by ---) will parse the first document. If you need to work with multi-document files, you can process each document separately by copying individual documents between the --- separators.
Is this JSON to YAML converter free?
Yes, it is completely free to use with no registration, sign-up, or limits. You can use it as many times as you need for personal, educational, or commercial projects without any restrictions.
Does it work offline?
Yes, once the page is loaded, all JSON and YAML conversion happens entirely in your browser using JavaScript. No server communication is needed, so you can use it even without an internet connection after the initial page load.
Can it handle large files?
Yes, this tool can handle moderately large files efficiently. Since all processing is done client-side, the performance depends on your device's capabilities. For very large files (several MBs), conversion may take a few extra moments, but the results are just as accurate.
Is my data secure?
Absolutely. All JSON and YAML conversion happens directly in your browser using JavaScript. Your data is never sent to any server, stored, or logged. This ensures complete privacy and security for sensitive information like API keys, configuration files, deployment settings, and credentials.
Extracted YAML Comments