YAML to JSON Converter
Parse YAML files and generate standard-compliant JSON with syntax verification and instant export.
- Runs in your browser
- Free, no signup
{
"server": {
"host": "127.0.0.1",
"port": 8080,
"ssl_enabled": true
},
"database": {
"driver": "postgresql",
"pool_size": 15,
"timeout_seconds": 30.5
},
"services": [
"auth",
"payments",
"notifications"
],
"debug_mode": false,
"fallback_url": null
}
Conversion runs entirely in your browser using local JavaScript — your YAML documents and configuration files are never uploaded to any server.
YAML is widely favored for human-edited configuration files, but modern web services, REST APIs, databases, and schema validators require strictly formatted JSON. This online converter translates YAML configurations into validated JSON in milliseconds.
Paste any YAML document, Kubernetes manifest, or OpenAPI specification to inspect its equivalent JSON representation. Choose between readable 2-space or 4-space formatted JSON or single-line minified JSON for production payloads, with detailed line and column syntax diagnostics if parsing issues arise.
How to use this tool
- Paste your YAML document into the input editor or click "Load Sample" to populate a sample config.
- Select your preferred JSON output format (2 spaces, 4 spaces, or compact minified) in the options bar.
- The converter parses the YAML structure and outputs valid JSON immediately, highlighting any indentation or syntax errors with line indicators.
- Click "Copy" to transfer the JSON output to your clipboard, or "Download" to save a .json file locally.
- Use "Swap Sides" whenever you want to test reciprocal conversion from JSON back to YAML.
Robust YAML 1.2 Syntax Parsing and Type Translation
YAML supports diverse scalar representations including block scalars (|, >), flow mappings, explicit types, and boolean representations (true, false, yes, no, on, off). The converter normalizes these constructs into strict RFC 8259 JSON equivalents.
Numbers, floating-point decimals, exponential notations, and nested collections are faithfully translated without data loss or type coercion.
Transform OpenAPI, Swagger, and Cloud Configurations
Developers frequently need to convert OpenAPI/Swagger YAML definitions into JSON schemas for programmatic validation or documentation generation. ToolDuck delivers instantaneous conversion without needing CLI tools or terminal packages.
The tool verifies that the resulting JSON adheres to standard specification requirements, ready for ingestion by API gateways, Postman collections, or schema validators.
Clear Line and Column Indentation Error Reporting
YAML indentation mistakes (such as mixing tabs and spaces, or misaligned block sequence items) are notorious for causing cryptic errors. The converter pinpoints the precise line and column where parsing failed.
An actionable error banner displays the parser exception details so you can quickly isolate and fix indentation problems before deploying configurations.
Zero-Upload Security and Complete Confidentiality
YAML configuration files often contain private environment secrets, database hosts, and internal routing topology. Transmitting this data over public APIs is unacceptable.
All parsing and serialization occur entirely on your local device within the browser sandbox. No server communication takes place, guaranteeing absolute privacy.
Frequently asked questions
Can I produce minified (compact) JSON from YAML?
Yes. In the Indentation selector, choose "Compact (Minified)" to generate single-line JSON without extraneous whitespace, ideal for network payloads.
How does the parser handle YAML anchors and aliases (* and &)?
Standard YAML aliases and anchors are dereferenced and expanded into their corresponding JSON object values during conversion.
What happens if my YAML contains tabs instead of spaces?
YAML specifications forbid tab characters for indentation. If tabs are detected in indentation positions, the error banner will identify the offending line so you can replace tabs with spaces.
Can I convert multi-document YAML files (separated by ---)?
The converter focuses on single-document conversion. For multi-document streams, each document can be parsed individually to produce clean, valid JSON.
Are my files or YAML inputs uploaded to any server?
Never. All conversion logic executes client-side using JavaScript in your browser. No files, logs, or payload strings are sent to our servers.