TOML to JSON/YAML Converter

Convert TOML to JSON or YAML online. Parse and validate TOML configuration files with support for tables, arrays, inline tables, multiline strings, and all TOML data types.

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Features

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Bidirectional Conversion

Convert TOML to JSON, TOML to YAML, or JSON back to TOML. Full support for nested structures and all TOML data types.

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TOML Validation

Validate TOML syntax with detailed error messages. Catch formatting issues, invalid keys, and type errors before deployment.

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Full TOML Support

Handle tables, arrays of tables, inline tables, multiline strings, integers, floats, booleans, dates, and all TOML v1.0 features.

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Instant & Private

All parsing and conversion happens in your browser. No server uploads. Works offline. Your configuration files stay private.

Convert and Parse TOML Configuration Files

TOML (Tom's Obvious, Minimal Language) is a popular configuration file format that balances human readability with machine parseability. It's widely used in modern development tools like Rust's Cargo, Python's Poetry, Hugo static site generator, and many DevOps applications. This converter helps you parse TOML files, validate their syntax, and convert them to JSON or YAML for use with tools that don't natively support TOML.

Understanding TOML Syntax

TOML uses a simple key-value syntax similar to INI files but with richer data types and nested structures. Basic key-value pairs use the format `key = "value"`. Tables (objects) are defined using `[table.name]` syntax, and array-of-tables use `[[array.name]]` for repeated sections. TOML supports strings (basic, literal, and multiline), integers (decimal, hex, octal, binary), floats (including infinity and NaN), booleans, dates and times with timezone support, arrays, and nested tables. Comments start with `#` and continue to the end of the line.

TOML vs JSON vs YAML

TOML is designed to be more readable than JSON while being more structured and unambiguous than YAML. Unlike JSON, TOML doesn't require quotes around keys, supports comments, and uses a flatter table syntax that's easier to navigate in large configuration files. Compared to YAML, TOML has fewer syntactic surprises -- no significant whitespace, no confusing yes/no/on/off boolean interpretations, and clearer nesting rules. The trade-off is that TOML can be more verbose for deeply nested structures, where JSON's bracket syntax or YAML's indentation might be more compact.

Common TOML Use Cases

Frequently Asked Questions

What is TOML? ▼
TOML (Tom's Obvious, Minimal Language) is a configuration file format designed to be easy to read and write. It uses a simple key-value syntax with support for nested tables, arrays, strings, numbers, booleans, and dates. TOML is popular for configuration files in Rust (Cargo.toml), Python (pyproject.toml), and many other tools. It aims to be more readable than JSON and more structured than INI files.
How do TOML tables work? ▼
TOML tables are sections that group related key-value pairs. Standard tables use [table.name] syntax, while array-of-tables use [[array.name]] for multiple entries. Tables can be nested using dot notation. For example, [database.server] creates a 'server' table within the 'database' table. Tables make TOML files well-organized and easy to navigate.
What data types does TOML support? ▼
TOML supports strings (basic, literal, multiline), integers (decimal, hexadecimal, octal, binary), floats (including infinity and NaN), booleans (true/false), datetime values (with timezone support), arrays (homogeneous or mixed), and tables (nested objects). This rich type system makes TOML suitable for complex configuration needs while remaining human-readable.
Can I convert JSON back to TOML? ▼
Yes! This tool supports bidirectional conversion. You can convert TOML to JSON or YAML, and also convert JSON back to TOML format. The converter handles nested objects, arrays, and all standard JSON data types, producing clean, readable TOML output with proper table syntax.
What are inline tables? ▼
Inline tables are a compact way to define tables on a single line using curly braces. For example: point = { x = 1, y = 2 }. They're useful for small, self-contained objects. Inline tables cannot span multiple lines and are best for simple structures. For complex nested data, standard table syntax is more readable.
How do multiline strings work in TOML? ▼
TOML supports multiline strings using triple quotes (""" for basic strings or ''' for literal strings). Basic multiline strings allow escape sequences and trim leading whitespace on each line. Literal multiline strings preserve all characters exactly as written, including backslashes. This makes TOML excellent for configuration with long text blocks or file paths.
Does this tool validate TOML syntax? ▼
Yes! The tool validates TOML syntax and displays clear error messages if parsing fails. It checks for proper key-value formatting, table syntax, array structure, string quotes, and data types. Validation errors show the line number and description of the problem, helping you fix syntax issues quickly.
What are common TOML use cases? ▼
TOML is widely used for configuration files: Rust's Cargo.toml for package management, Python's pyproject.toml for project metadata and tool configuration, Hugo static site generator config, and many DevOps tools. Its human-readable syntax makes it ideal for version-controlled configuration that developers edit frequently.

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