Free online data format converter. Convert between JSON, YAML, XML, TOML, and CSV instantly with real-time validation. Privacy-first, client-side processing.
Data format conversion transforms structured data between different serialization formats — JSON, XML, YAML, CSV, TOML, Protocol Buffers, and more. Each format has distinct strengths: JSON is the standard for web APIs, XML dominates enterprise integrations, YAML excels at human-readable configuration, and CSV is universal for tabular data exchange.
Converting between formats is a daily task for developers, data engineers, and system administrators who work with multiple systems, APIs, and tools that expect data in different formats.
| Format | Human-Readable | Comments | Data Types | Best For |
|---|---|---|---|---|
| JSON | Good | No | String, number, boolean, null, array, object | Web APIs, configuration, NoSQL databases |
| XML | Moderate | Yes | String (with schemas for typing) | Enterprise integration, SOAP, document markup |
| YAML | Excellent | Yes | Same as JSON + dates, multiline strings | Configuration files, Kubernetes, CI/CD |
| CSV | Good (tabular) | No | String only (untyped) | Spreadsheets, data export/import, analytics |
| TOML | Excellent | Yes | String, integer, float, boolean, datetime | Application configuration (Rust, Python) |
| INI | Excellent | Yes | String only | Legacy configuration files |
All conversions happen entirely in your browser using client-side JavaScript. No data is sent to our servers or stored anywhere. Your files are processed in memory and discarded immediately after conversion.
You can convert between JSON, YAML, XML, TOML, and CSV in any direction. The tool supports bidirectional conversion with real-time validation for all format combinations.
CSV is a flat, tabular format designed for simple row-and-column data. When converting nested structures to CSV, the tool automatically flattens them using dot notation (e.g., address.city). For complex nested data, consider using JSON, YAML, or XML instead.
No, YAML comments cannot be preserved when converting to other formats because JSON, XML, TOML, and CSV do not support comments in their specifications. Comments are automatically stripped during conversion.
XML attributes are converted to object properties with an @ prefix (e.g., @id, @class) when converting to JSON, YAML, or TOML. This preserves the attribute information while maintaining valid syntax in the target format.
TOML specification does not support null/nil values. If your data contains null values, you must either remove them or replace them with empty strings or default values before converting to TOML.
For best performance, we recommend files under 5MB. Files over 10MB may cause browser slowdowns or crashes. For very large files, consider using command-line tools like yq, jq, xmllint, or dedicated conversion libraries in your programming language.
The auto-detect feature analyzes your input using format-specific patterns (JSON braces, YAML colons, XML tags, TOML sections, CSV delimiters) and validates against each format specification until it finds a match. It works best with well-formed, valid data.
Currently, the tool processes one file at a time. For batch conversion of multiple files, consider using command-line tools or scripting with libraries like js-yaml, fast-xml-parser, or papaparse in your own automation workflows.
The tool supports UTF-8 encoding by default, which covers all modern text formats and international characters. If you have files in other encodings (like ISO-8859-1 or Windows-1252), convert them to UTF-8 first for best results.