Developer Tool

YAML ↔ JSON
Converter

Convert between YAML and JSON instantly — with live bidirectional conversion, real-time error detection, and ready-to-use Kubernetes, GitHub Actions, and Docker Compose templates.

Templates:
INPUT
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OUTPUT
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YAML vs JSON — When to Use Which?

YAML (YAML Ain't Markup Language) is a human-readable data serialization standard that uses indentation to represent structure. It is the preferred format for configuration files in Kubernetes, GitHub Actions, Docker Compose, Ansible, and Helm charts because it is easy to write and supports comments.

JSON (JavaScript Object Notation) uses explicit braces, brackets, and quoted keys. It is the universal standard for REST API responses, configuration in package.json, tsconfig.json, and any context where a strict, unambiguous format is required.

Both formats represent identical data structures. Every valid JSON document is also valid YAML (YAML is a superset of JSON). This tool converts instantly in both directions, preserving all values, arrays, nested objects, and null values.

YAML vs JSON — Full Comparison

FeatureYAMLJSON
Comments✓ Supported (#)✗ Not supported
String quotesOptional for simple stringsRequired on all strings
Trailing commasN/A✗ Not allowed
Multi-line strings✓ Block (|) and folded (>)Requires \n escapes
Anchors & aliases✓ Reuse values with & and *✗ Not supported
ReadabilityHigh — no brackets or quotesMedium — verbose for nested data
Parser availabilityMost languagesUniversal — built-in everywhere
Common useKubernetes, GitHub Actions, Docker, Ansible, HelmREST APIs, package.json, tsconfig.json
JSON superset✓ All valid JSON is valid YAMLN/A
Binary data✓ via Base64 with !!binary tagVia Base64 string

YAML Syntax Quick Reference

Strings: name: Alice — no quotes needed for simple strings. Quote with " or ' if the value contains : # @ { } [ ] or starts with a special character.

Numbers: port: 3000 or ratio: 1.5 — YAML auto-detects integers and floats.

Booleans: enabled: true or active: false — use lowercase. Avoid yes/no (YAML 1.1 only).

Null: value: ~ or value: null

Lists: Each item on a new line starting with -:
tags:
  - backend
  - devops

Multi-line string (literal block): Use | to preserve line breaks, > to fold them into spaces.

Indentation: Always use spaces, never tabs. 2 spaces is the standard convention.

Common YAML ↔ JSON Conversion Scenarios

Here are the most common real-world situations where developers need to convert between YAML and JSON:

Kubernetes manifests → Helm values: Kubernetes resources are written in YAML, but tooling like Terraform's Kubernetes provider or some CI systems accept only JSON. Paste your Deployment or CronJob YAML here to get the equivalent JSON representation instantly.

GitHub Actions workflows → API payloads: The GitHub Actions API (POST /repos/{owner}/{repo}/actions/workflows/{workflow_id}/dispatches) accepts JSON. If you have a .github/workflows/ YAML file, convert it to JSON to understand the structure for API calls or repository dispatch events.

Docker Compose → Portainer / Compose API: Some Docker management tools accept a Compose file as inline JSON rather than a YAML file. Convert your docker-compose.yml to JSON for these integrations.

Ansible playbooks → JSON inventories: Ansible natively supports both YAML and JSON inventory files. When integrating with an external CMDB or asset management system that outputs JSON, convert it to YAML for readability in version control.

OpenAPI specs: OpenAPI/Swagger specifications are commonly written in YAML for readability but many code generators and validators require JSON. Convert the spec in either direction with zero manual editing.

YAML ↔ JSON Converter vs Other Tools — What's Different

Most YAML-JSON converters online are single-direction, have no error messages, and offer no context for developers who work with Kubernetes or CI/CD configs. Here's what this tool does differently:

Truly bidirectional. One tool converts in both directions. Auto-detect mode identifies whether your input is YAML or JSON automatically — no need to select a direction first.

Production-ready templates. The Kubernetes CronJob, GitHub Actions, and Docker Compose templates are complete and correct — not simplified toy examples. Load one, convert it to JSON, and use it directly.

Real-time error messages. Syntax errors show the exact line number and problem description as you type — the same quality of feedback you'd get from a terminal YAML parser.

Download as file. Save the converted output as a .yaml or .json file directly — useful when converting config files between formats for tools that only accept one format.

YAML ↔ JSON — FAQ

What is YAML?
YAML (YAML Ain't Markup Language) is a human-readable data serialization format that uses indentation instead of brackets and braces. It supports comments and is widely used in Kubernetes, GitHub Actions, Docker Compose, Ansible, and Helm.
Can YAML have comments? Can JSON?
YAML supports comments (lines starting with #). Standard JSON does not support comments. JSONC (JSON with Comments) is a non-standard extension used in VS Code config files.
What is a Kubernetes CronJob YAML?
A Kubernetes CronJob is a workload that runs Jobs on a schedule using a cron expression. It is defined in YAML with spec.schedule containing the cron string. Use the template above to see a complete example.
Why does my YAML fail to convert?
Common YAML errors: inconsistent indentation (tabs vs spaces), missing quotes on strings with special characters (:, #, @), unclosed brackets or braces, and duplicate keys. The error message above the output shows the exact line and cause.
What are YAML anchors and aliases?
Anchors (&name) and aliases (*name) let you reuse parts of a YAML document. They are YAML-only features with no direct JSON equivalent. When converting to JSON, anchors are resolved and the referenced values are inlined.
Does YAML support null, true/false, and numbers?
Yes. YAML represents null as ~ or the word null. Booleans are true/false (or yes/no in YAML 1.1). Numbers are auto-detected. This converter outputs standard JSON-compatible types.

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