Data Format Converter
DataConvert between JSON, YAML, TOML, XML and CSV in one place with a single paste and instant preview for seamless multi-format config and data conversion.
name: OLTool version: '2.0' tags: - json - yaml - toml config: theme: dark indent: 2
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About Data Format Converter
Development constantly involves converting between JSON, YAML, TOML, XML, and CSV: migrating config files, exporting API data, modeling tabular data, or mashing formats together in a pipeline. Instead of hopping between a dozen one-way tools, this one brings them together — pick a source and target format, paste once, and convert in any direction, with a one-click swap that feeds the output back as input for round-trip checks. For example, JSON {"name":"Tom","age":20} becomes YAML name: Tom / age: 20, or back again, with nesting preserved automatically. A few caveats keep results predictable: CSV export needs an array of objects and treats the first row as the header on import; YAML's implicit type inference can reinterpret strings like on or date-like values as booleans or timestamps; and extremely nested inline TOML or namespaced XML is best handled by the dedicated tools. Everything runs locally, so sensitive config and API data never leave your machine.
How to Use
- Open the Data Format Converter tool
- Import or paste the data to process
- Adjust the output options as needed
- Click the Process button; results appear in real time
- Copy or export the result
Use Cases
- Migrate config files — Turn YAML config into TOML or JSON to move seamlessly between toolchains.
- Export API data — Convert a JSON API response to CSV and import it straight into Excel or analytics tools.
- Cross-format comparison — View the same data as JSON or YAML to quickly understand structural differences.
- Tabular to structured — Convert a CSV table into a JSON array of objects for frontend rendering or API mocks.
- Integrate legacy XML — Turn XML into JSON for modern frontends, or generate XML payloads in reverse.
- Transform env files — Convert a flat .env key-value list into JSON or YAML for structured config injection in containers.
- Generate sample data — Write a quick CSV table in a spreadsheet, then convert to JSON objects for API mock endpoints.
FAQ
Which conversions are supported?
Any-direction conversion among JSON, YAML, TOML, XML and CSV, using a unified JS object as the intermediate representation.
Any requirements for CSV?
Exporting CSV requires an array of objects (one object per row); the tool uses the union of fields as headers. When importing CSV, the first row is treated as the header.
Do TOML/XML support complex structures?
Common tables, arrays, nesting and attributes are supported. For extremely complex TOML (e.g. nested inline tables) or namespaced XML, use the dedicated tool.
What does the swap button do?
It swaps the source/target formats and moves the current output into the input box, making round-trip conversion and verification easy.
Can types be lost during conversion?
Most scalars are faithfully preserved, but YAML's implicit type inference and the differing support for null and attributes in TOML/XML can turn a few values into strings — verify key fields afterward.
Is my data uploaded?
No. All parsing and serialization happens locally in your browser, making it safe for configs or API data that contain sensitive fields.