JSON / YAML / TOML Converter
How to Use the JSON / YAML / TOML Converter
Paste your data in JSON, YAML, or TOML format into the input field. The tool auto-detects the input format. Select your desired output format and click Convert. The converter handles nested objects, arrays, and all standard data types. Copy the converted output with one click.
Understanding Configuration Format Differences
Modern software projects use configuration files extensively, and different tools prefer different formats. Docker Compose and Kubernetes use YAML. Node.js projects use JSON for package.json. Rust and Python tooling use TOML. When moving data between systems or converting example configurations, you need a reliable way to transform between these formats.
JSON (JavaScript Object Notation)
JSON is the most universal data interchange format. Its strict syntax with required quotes around keys, no trailing commas, and no comments makes it predictable to parse but tedious to write by hand. JSON is the standard for API request and response bodies, configuration files in the JavaScript ecosystem, and data storage.
YAML (YAML Ain’t Markup Language)
YAML uses indentation to represent structure, eliminating the visual noise of braces and brackets. It supports comments (lines starting with #), multi-line strings, and anchors that let you reference values defined elsewhere in the file. YAML is the dominant format for DevOps tools, CI/CD pipelines, and cloud infrastructure configuration.
TOML (Tom’s Obvious Minimal Language)
TOML uses an INI-like syntax with clear section headers in square brackets. It is designed to be unambiguous and easy to read. TOML maps directly to a hash table, making it simple to implement in any language. It is the configuration format for Rust’s Cargo, Python’s pyproject.toml, and Hugo static sites.
Format Comparison
| Feature | JSON | YAML | TOML |
|---|---|---|---|
| Comments | No | Yes (#) | Yes (#) |
| Trailing commas | No | N/A | No |
| Multi-line strings | No | Yes | Yes (""") |
| Date type | No (string) | Yes | Yes |
| Strict parsing | Yes | Moderate | Yes |
| Readability | Medium | High | High |
| Nesting depth | Unlimited | Unlimited | Limited (complex) |
Common Conversion Scenarios
Docker Compose to JSON
Docker Compose files are written in YAML, but some orchestration tools accept JSON configuration. Converting from YAML preserves the structure while adding the explicit syntax that JSON requires. Note that YAML comments are lost during conversion since JSON has no comment syntax.
Package Configuration Migration
When migrating a Python project from setup.cfg to pyproject.toml, or converting a JavaScript project’s configuration, this tool helps verify that the structure translates correctly. Paste the source configuration, convert it, and compare the output to ensure all values are preserved.
API Response to Configuration
API responses come in JSON, but you may want to save them as YAML configuration for readability or TOML for use in your project. This converter handles the transformation while preserving data types and nested structures.
Handling Edge Cases
Some features do not translate perfectly between formats. YAML comments are lost when converting to JSON or TOML. YAML anchors and aliases are expanded into their full values. TOML’s native date type is converted to an ISO 8601 string in JSON. The converter handles these edge cases automatically, but be aware of them when round-tripping data between formats.
For working with CSV data that needs to be converted to JSON, use the CSV to JSON Converter. If you need to convert markdown documentation that contains configuration examples, the Markdown to HTML Converter can render the output for preview.
Related Tools
- CSV to JSON Converter - Convert spreadsheet data to JSON or vice versa
- Markdown to HTML Converter - Convert documentation between formats
- AI Token Counter - Measure token count of JSON schemas for AI APIs
Frequently Asked Questions
What is the difference between JSON, YAML, and TOML?
JSON uses braces and quotes with strict syntax. YAML uses indentation and is more human-readable, supporting comments. TOML uses an INI-like syntax with sections and is designed for configuration files. Each is preferred by different tools and ecosystems.
Can YAML do things that JSON cannot?
Yes. YAML supports comments, multi-line strings, anchors and aliases for reusing values, and multiple documents in a single file. JSON does not support any of these features. However, JSON is stricter, which makes it less prone to formatting errors.
Which configuration format should I use for my project?
Use JSON for package.json and API responses where strictness matters. Use YAML for Docker Compose, Kubernetes, CI/CD pipelines, and files that benefit from comments. Use TOML for Rust (Cargo.toml), Python (pyproject.toml), and simple key-value configuration.