Paste YAML to get validated JSON, or paste JSON to produce clean YAML, featuring syntax validation, minification toggle, and one-click copying. The tool runs in your browser without any server uploads.
Key Features of YAML ↔ JSON Converter
- Bidirectional Conversion Switch between YAML → JSON and JSON → YAML with a single dropdown. Both directions validate the input and show clear error messages if parsing fails.
- YAML Anchors, Aliases & Multiline Strings Anchors (&), aliases (*), and merge keys (<<) are fully resolved during parsing. Literal block scalars (|) and folded scalars (>) are correctly converted to JSON strings.
- JSON Formatting Options Choose 2-space, 4-space, or minified JSON output when converting from YAML. The formatting option applies live as you type.
- Monaco Editor with Language Highlighting Both panels use the Monaco editor (VS Code's engine) with syntax highlighting that switches automatically between YAML and JSON based on the selected conversion direction.
- File Upload & Copy Upload .yaml, .yml, or .json files directly into the input panel. Copy both the input and output to your clipboard. All processing is client-side — nothing is sent to a server.
YAML ↔ JSON Converter Examples
Converting a YAML Server Config to JSON
Convert a typical application YAML configuration file to its JSON equivalent.
Input
server:
port: 8080
host: 127.0.0.1
database:
engine: postgresql
port: 5432
Output
{
"server": {
"port": 8080,
"host": "127.0.0.1"
},
"database": {
"engine": "postgresql",
"port": 5432
}
}
Converting JSON Back to YAML
Take a JSON object and produce a clean, human-readable YAML representation.
Input
{"name":"deploy","on":{"push":{"branches":["main"]}},"jobs":{"build":{"runs-on":"ubuntu-latest"}}}
Output
name: deploy
on:
push:
branches:
- main
jobs:
build:
runs-on: ubuntu-latest
How to Use YAML ↔ JSON Converter
-
1. Paste YAML or JSON
Enter your YAML or JSON data into the input panel.
-
2. Choose Conversion Direction
Select YAML → JSON or JSON → YAML using the direction toggle.
-
3. Copy or Download the Result
The converted output appears right away. Copy it to your clipboard or download it as a file.
Common Use Cases for YAML ↔ JSON Converter
- Kubernetes & Docker Config Conversion Kubernetes manifests and Docker Compose files are written in YAML, but many API clients and tools expect JSON. Convert configs between formats without manually rewriting them.
- CI/CD Pipeline Config Debugging GitHub Actions, GitLab CI, and CircleCI use YAML. Convert your pipeline config to JSON to inspect its parsed structure and verify nested values look correct.
- JSON API Response to Config File When a REST API returns a JSON object you want to use as a YAML config file, convert it in one step and adjust from there.
- Validating YAML Syntax Use the converter as a YAML linter — if conversion fails, the error message pinpoints the exact line and reason the YAML is invalid.
The Technical Details
YAML parsing uses the js-yaml library, which implements the YAML 1.2 specification. It handles anchors, aliases, merge keys, multiline scalars, and complex nested structures that a simple regex-based parser would miss.
For YAML → JSON, the parsed JavaScript object is serialised with JSON.stringify. The indent level (2, 4, or minified) is passed as the third argument. Since JSON does not support comments, anchors, or aliases, these are resolved to their literal values during the js-yaml parse step.
For JSON → YAML, the input is parsed with JSON.parse and then serialised back to YAML using jsyaml.dump with indent: 2 and noRefs: true to prevent js-yaml from re-introducing anchors and aliases, keeping the output readable.
Frequently Asked Questions
Are YAML anchors and aliases supported?
Yes. YAML anchors (&) and aliases (*) are resolved during parsing, and the referenced values are inlined in the output.
How are multiline strings handled?
YAML literal block scalars (|) and folded scalars (>) are preserved and converted to JSON strings with newlines or spaces.
Is any data sent to a server?
No. All conversion runs in your browser. Nothing is ever uploaded to a server.
Does it output strict JSON?
Yes. The JSON output uses strict double-quoted keys and values, with no trailing commas or comments.