YAML ↔ JSON Converter

YAML to JSON Converter — Free Online YAML ↔ JSON Tool

Paste your YAML config or JSON data, choose the direction, and get the converted output in seconds — entirely in your browser, no upload, no account, no server involved.

Whether you're building Kubernetes manifests, debugging an OpenAPI spec, or transforming an API response into a readable config file, this converter handles both directions: YAML to JSON and JSON to YAML.

How to Use This YAML to JSON Converter

1. Choose the direction — select "YAML → JSON" or "JSON → YAML" using the toggle at the top.
2. Paste your input — drop your YAML or JSON into the left panel. You can also click "Paste" to pull directly from your clipboard.
3. Copy or download the result — the converted output appears instantly on the right. Click "Copy" or download the file with one click.

The converter validates your input in real time. A green "Valid" badge confirms your input is well-formed before you copy the result.

YAML to JSON — What It Does and Why You Need It

YAML (YAML Ain't Markup Language) is the standard format for configuration files across the DevOps ecosystem. Kubernetes manifests, Docker Compose files, GitHub Actions workflows, Ansible playbooks, Helm Charts, and OpenAPI specifications are all written in YAML because its indentation-based syntax is human-readable and supports inline comments.

JSON (JavaScript Object Notation) is the standard for data exchange in web applications, REST APIs, and NoSQL databases. Most frameworks and tools consume JSON natively.

Converting YAML to JSON is necessary when you need to feed YAML-based config data into an API, a JavaScript application, or any tool that only accepts JSON. This converter parses your YAML, validates the structure, and outputs clean, properly indented JSON. One important note: JSON does not support comments, so any YAML comments (#) are removed during conversion. YAML anchors and aliases are fully resolved and inlined in the output.

JSON to YAML — The Reverse Direction

Converting JSON to YAML takes machine-generated or API-sourced JSON and transforms it into the human-friendly YAML format — useful when you want to use that data in a config file, add inline comments for documentation, or integrate it into a Kubernetes manifest or GitHub Actions workflow.

Since YAML 1.2 is a superset of JSON, every valid JSON document is also valid YAML. The conversion from JSON to YAML is always lossless: all data types, nesting levels, and values are preserved. The output uses 2-space indentation per level, making it immediately readable and ready to extend.

Common Use Cases

• Kubernetes and Helm: Feed YAML manifests into JSON-only CI/CD tools, or convert Helm Chart values from JSON back to YAML.
• OpenAPI and Swagger: Many API specs are written in YAML. Convert to JSON when your toolchain requires it, or go back to YAML for human review.
• Docker Compose and Ansible: Transform Docker Compose service configs or Ansible playbooks between formats depending on the consuming tool.
• REST API development: Convert JSON API responses into YAML for use in config files or documentation templates.
• GitHub Actions workflows: Debug or adapt workflow YAML files by converting to JSON for schema validation or tooling that only reads JSON.

Frequently Asked Questions

What is the difference between YAML and JSON?

YAML and JSON are both data serialization formats, but they serve different audiences. YAML uses indentation and minimal punctuation, making it ideal for config files that humans read and edit frequently — Kubernetes, Docker Compose, GitHub Actions, and Ansible all use YAML. JSON uses braces and brackets, has stricter syntax, and is faster to parse, making it the standard for REST APIs and data exchange between services. YAML 1.2 is a superset of JSON, meaning every valid JSON document is also valid YAML.

Are comments preserved when converting YAML to JSON?

No. JSON does not support comments, so any comments in your YAML input (lines starting with #) are removed during the conversion. If you need to document your configuration, keep the original YAML file alongside the generated JSON.

What happens to YAML anchors and aliases during conversion?

YAML anchors (&) and aliases (*) are fully resolved during conversion to JSON. The referenced value is inlined at every point where the alias appears. The resulting JSON is fully expanded and contains no YAML-specific constructs.

Is converting JSON to YAML lossless?

Yes. Since YAML 1.2 is a superset of JSON, converting JSON to YAML is always lossless. All data types, nested structures, arrays, booleans, numbers, and null values are preserved exactly. The reverse (YAML to JSON) can lose comments and anchors, but all data values are preserved.

Is my data safe when using this tool?

Yes. All conversion runs entirely in your browser using JavaScript. No YAML or JSON data is ever sent to a server, stored, or logged. You can safely convert sensitive configuration files, API keys in config templates, and infrastructure definitions — nothing ever leaves your device.

Resources

• YAML 1.2 Specification — yaml.org — The official YAML 1.2 spec that defines how YAML is a superset of JSON.
• JSON.org — The canonical reference for the JSON data format, with syntax diagrams.
• Kubernetes YAML vs JSON — kubernetes.io — Official guidance on when Kubernetes accepts YAML or JSON for resource definitions.