JSON ↔ YAML Converter

Convert between JSON and YAML formats instantly.

100% Private — Your files never leave your device.

All processing happens in your browser. Nothing is uploaded to any server.

JSON Input

YAML Output

Loading YAML library...

Note: YAML comments are not preserved when converting to JSON (JSON does not support comments). YAML anchors and aliases are resolved during conversion.

How it works

When to Convert JSON to YAML

Common scenarios for JSON → YAML conversion:

Kubernetes configs: Convert JSON exports to YAML for human-readable deployment manifests
CI/CD pipelines: GitHub Actions, GitLab CI, and CircleCI all use YAML
Docker Compose: Compose files are always YAML
Ansible playbooks: Infrastructure as code in YAML format
Human editing: YAML is easier to read and edit by hand than JSON

When to Convert YAML to JSON

Common scenarios for YAML → JSON conversion:

API integration: Most REST APIs expect JSON, not YAML
Programmatic editing: JSON is easier to manipulate with code (jq, Python, JavaScript)
Validation: JSON schemas are more common than YAML schemas
Debugging: JSON’s strict syntax makes errors more obvious

Format Comparison

# YAML                          // JSON
name: CalcRun                   {"name": "CalcRun",
version: 1.0                     "version": 1.0,
features:                        "features": [
  - calculators                    "calculators",
  - converters                     "converters"
                                 ]}

Feature	JSON	YAML
Comments	Not supported	`# comment`
Quotes required	Always (for keys/strings)	Only when needed
Multi-line strings	Escaped `\n`	`\|` (literal) or `>` (folded)
Data reuse	Not supported	Anchors `&` and aliases `*`
File size	Larger (verbose)	Smaller (compact)
Parsing speed	Faster	Slower
Ambiguity	None	Some (`yes` = boolean)

How It Works

This tool uses js-yaml, the most popular YAML library for JavaScript with 44M+ weekly npm downloads. It fully supports the YAML 1.2 specification. All conversion happens in your browser — no data is sent to any server.

Real-World Examples

Converting a Docker Compose file to JSON for programmatic editing

Mode: YAML to JSON Input File: docker-compose.yml

A DevOps engineer needs to programmatically modify a Docker Compose configuration. Converting the YAML to JSON produces a structured object that can be manipulated with jq or any JSON library. The nested service definitions, port mappings, and volume mounts are all preserved with correct data types — numbers stay as numbers, booleans as booleans.

Converting a JSON API schema to YAML for Kubernetes config

Mode: JSON to YAML Input File: deployment.json

A developer has a Kubernetes deployment manifest in JSON format from an API export, but their team uses YAML for all Kubernetes configs. Converting produces clean, human-readable YAML with proper indentation. The 180-line JSON becomes 120 lines of YAML — more compact because YAML doesn't need braces, brackets, or quotes for simple strings.

Converting CI/CD pipeline config between formats

Mode: JSON to YAML Input File: pipeline.json

A team is migrating from a CI system that uses JSON configs to one that uses YAML (like GitHub Actions). Converting the 50-step pipeline configuration takes under a second. Arrays become dash-prefixed lists, nested objects become indented blocks, and the overall structure is preserved exactly.

Frequently Asked Questions

What is the difference between JSON and YAML?

JSON uses braces {}, brackets [], quotes, and commas for structure. It's strict and machine-friendly. YAML uses indentation and colons for structure — no braces or brackets needed. YAML supports comments (# comment), multi-line strings, and anchors/aliases for reuse. JSON is a subset of YAML (valid JSON is valid YAML). YAML is preferred for configuration files; JSON is preferred for data exchange and APIs.

Can YAML comments survive conversion to JSON and back?

No. JSON does not support comments, so any YAML comments are lost when converting to JSON. If you convert JSON back to YAML, the comments will not be restored. This is an inherent limitation — not a bug. If you need to preserve comments, keep a copy of the original YAML file.

How does YAML handle data types?

YAML automatically infers types: 'true'/'false' become booleans, '42' becomes an integer, '3.14' becomes a float, 'null'/'~' become null, and unquoted strings without special characters become strings. This can cause surprises — for example, 'yes' becomes boolean true, and '1.0' becomes a float. To force a string, wrap it in quotes: '"yes"' or "'1.0'".

Is YAML a superset of JSON?

Yes, as of YAML 1.2. Any valid JSON document is also valid YAML. This means you can paste JSON directly into a YAML parser and it will work. However, YAML adds features that JSON doesn't have: comments, multi-line strings (| and >), anchors (&anchor/*alias), type tags (!!str, !!int), and more compact syntax.

Which format should I use for configuration files?

YAML is generally preferred for human-edited configuration files (Docker Compose, Kubernetes, GitHub Actions, Ansible) because it's more readable and supports comments. JSON is preferred for machine-generated or machine-consumed data (API responses, package.json, tsconfig.json) because it's unambiguous and universally supported. Use YAML when humans read it; use JSON when machines read it.

What happens to YAML anchors and aliases during conversion?

YAML anchors (&name) and aliases (*name) are resolved during conversion to JSON. The referenced data is expanded inline — each alias becomes a full copy of the anchored data. This means the JSON output may be larger than the YAML input if anchors are used extensively. Converting back to YAML will not recreate the anchors.

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