CosmoTools

Free online tool

JSON to YAML Converter

Convert JSON into readable YAML without uploading your data.

Convert JSON to YAML

Conversion happens locally in your browser.

How to convert JSON to YAML

Paste valid JSON, select Convert to YAML, then copy the result or download it. Objects become mappings and arrays become sequences.

Readable configuration output

The converter uses two-space indentation and quotes values when YAML could otherwise interpret them as another type.

Frequently asked questions

Is the conversion performed locally?

Yes. The JSON is converted entirely in your browser.

Can I download the YAML?

Yes. You can copy the result or download a .yaml file.

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How the tool works

Paste valid JSON and convert objects to YAML mappings and arrays to sequences. The output uses consistent indentation and quotes values when an unquoted representation could be interpreted as another YAML type. Copy the text or download a .yaml file.

Supported input and output

JSON strings, numbers, booleans, null values, objects, and arrays all have YAML equivalents. Because YAML has additional syntax and implicit types, the converter favors an explicit and predictable representation rather than the shortest possible output.

Practical example

A JSON configuration containing services, ports, and environment arrays becomes a readable YAML hierarchy suitable for review. The result can provide a starting point for CI pipelines, containers, static-site configuration, or infrastructure files.

Common use cases

JSON to YAML conversion is useful when migrating configuration, translating generated JSON for a YAML-based tool, preparing examples for documentation, or comparing the two representations. Local conversion protects configuration values from third-party uploads.

Limits and important checks

The conversion preserves data but not JSON comments because JSON has no comment syntax. It cannot infer tool-specific YAML tags, anchors, aliases, or preferred key ordering. Validate the result with the target application before deploying it.

Privacy and local processing

Unless the tool explicitly identifies an external lookup, input and generated output are processed in your browser and are not uploaded to CosmoTools. Avoid placing secrets in any web page and review downloaded results before using them in production.

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