What is the difference between JSON and YAML?

JSON uses braces {} and brackets [] with strict quotation requirements, while YAML uses indentation for structure. YAML is more human-readable and supports comments, making it preferred for configuration files. JSON is better for data interchange between applications due to its strict format.

Is this JSON to YAML converter free?

Yes, our JSON to YAML converter is completely free with no usage limits. There's no signup required, and your data is processed entirely in your browser without being sent to any server.

Can I convert YAML back to JSON?

Yes! Use our YAML to JSON converter at /yaml-to-json for reverse conversion. Both tools work instantly in your browser.

Does the converter preserve data types?

Yes, our converter accurately preserves all JSON data types including strings, numbers, booleans, null values, nested objects, and arrays in the YAML output.

Can I use this for OpenAPI/Swagger files?

Absolutely. Our converter handles OpenAPI 3.0 and Swagger 2.0 specification files, properly converting the entire API definition structure to YAML format.

Is my data secure when using this converter?

Yes. All conversion happens locally in your browser using JavaScript. Your JSON data is never sent to any server or stored anywhere. Your data remains completely private.

What if my JSON has errors?

The converter validates your JSON before conversion. You'll see a clear error message identifying the problem, such as missing commas, unmatched brackets, or invalid characters.

Can I convert large JSON files?

Yes. The converter runs in your browser and can handle files as large as your browser's memory allows. For extremely large files, consider using command-line tools like yq or jq.

Does the output preserve key order?

Yes. The converter maintains the same key order from your original JSON. Keys appear in the YAML output in the same sequence you provided them.

What indentation does the YAML output use?

The default output uses 2-space indentation, which is the most common YAML style. You can change this to 4 spaces if your project requires it.

Services · Networks · Volumes

Docker Compose JSON to YAML
Converter

Generate a clean docker-compose.yml from JSON in seconds. Ideal for converting programmatically built service definitions into the YAML format Docker Compose expects. Free, instant, and browser-based.

JSON

YAML

How to Convert JSON to Docker Compose YAML

Paste your compose JSON

Drop in the JSON representation of your services, networks, and volumes.

Get compose YAML

Properly indented docker-compose YAML appears instantly, with services as nested mappings.

Save as docker-compose.yml

Copy or download the output, then run docker compose up to bring your stack online.

Why Docker Compose Uses YAML

Docker Compose reads service definitions from a YAML file, conventionally named docker-compose.yml or compose.yaml. While the data could be expressed as JSON, Compose's tooling and documentation are built around YAML.

Teams often generate compose configurations programmatically — from templates, CI scripts, or infrastructure tools — which produces JSON. Converting that JSON to YAML gives you a file you can commit, review, and hand to docker compose directly.

Benefits for Container Workflows

Ready to Run

The YAML output is valid docker-compose syntax. Save it as docker-compose.yml and your stack is one command away.

Cleaner Reviews

Port mappings and environment blocks are far easier to scan in YAML than in nested JSON during code review.

Comment Your Stack

Explain why a service needs a specific volume or restart policy. YAML supports # comments that JSON cannot.

Local & Private

Your service config — including any credentials in environment blocks — is converted in-browser and never uploaded.

Frequently Asked Questions

Does the output work with docker compose up?

Yes. The converter produces standard YAML. Save it as docker-compose.yml in your project directory and run docker compose up — Compose parses it like any hand-written file.

How are environment variables handled?

Environment blocks convert directly. Whether your JSON uses a map of key-value pairs or an array of KEY=value strings, the equivalent YAML is produced and Compose accepts both forms.

Are port mappings preserved?

Yes. Port strings stay quoted in the YAML output, which is correct — Compose requires ports to be treated as strings to avoid the base-60 parsing issue.

Can I convert a single service?

Absolutely. Convert any valid JSON fragment, including a single service definition, then paste it under the services key of your compose file.

Which Compose version does it support?

The tool is version-agnostic — it converts whatever structure you provide, working for legacy version: "3.8" files and the current Compose Specification alike.

Related Tools & Resources

JSON to YAML Converter
General-purpose JSON to YAML conversion.
YAML to JSON Converter
Reverse the conversion back to JSON.
All Converters
Browse every JSON-to-YAML use case.
Docker Compose File Reference
Official documentation.

Docker Compose JSON to YAMLConverter