TOML Converter
Convert between TOML, JSON, and YAML formats
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How to Use
Paste or Type Input
Enter your text, code, or data into the input area.
Choose Options
Select the transformation or format you want to apply.
Copy the Result
Copy the output to your clipboard with one click.
Why Use This Tool
100% Free
No hidden costs, no premium tiers — every feature is free.
No Installation
Runs entirely in your browser. No software to download or install.
Private & Secure
Your data never leaves your device. Nothing is uploaded to any server.
Works on Mobile
Fully responsive — use on your phone, tablet, or desktop.
TOML: Tom's Obvious Minimal Language for Configuration
Key Takeaways
- TOML is designed to be unambiguous and easy to read, with explicit typing for strings, integers, floats, booleans, dates, arrays, and tables.
- TOML is the standard configuration format for Rust (Cargo.toml), Python (pyproject.toml), and many modern tools.
- All conversion between TOML and JSON happens in your browser — your configuration data stays private.
TOML (Tom's Obvious Minimal Language) was created to be a minimal, unambiguous configuration file format that maps clearly to a hash table. Unlike YAML, which has complex features and implicit type coercion pitfalls, TOML aims for simplicity and explicit semantics. It has been adopted as the standard config format by Rust's Cargo, Python's pyproject.toml, and many other modern tools.
TOML is the official configuration format for over 150,000 Rust crates on crates.io.
Ecosystem Adoption
Key Concepts
Tables and Nested Tables
TOML uses [table] headers to define sections and [table.subtable] for nesting. This maps directly to JSON objects and makes configuration hierarchy immediately visible.
Explicit Type System
Unlike YAML where 'yes' becomes a boolean, TOML has unambiguous types: strings always use quotes, integers never have quotes, and dates follow RFC 3339 format.
Array of Tables
The [[array]] syntax creates arrays of tables (equivalent to JSON arrays of objects), enabling lists of structured configuration entries like multiple server definitions.
TOML vs. YAML vs. JSON
TOML trades YAML's flexibility for unambiguity and simplicity. It lacks YAML's anchors and aliases but avoids its pitfalls. JSON lacks comments and has more verbose syntax. TOML occupies the sweet spot.
Pro Tips
Use inline tables { key = 'value' } sparingly — they are best for small, single-line groupings.
TOML supports multi-line strings with triple quotes and literal strings with single quotes (no escape processing).
When converting JSON to TOML, deeply nested objects become long dotted table names — consider restructuring for readability.
TOML native date/time types (RFC 3339) are converted to strings in JSON — ensure your application handles the conversion correctly.
All TOML/JSON conversion is performed entirely in your browser. Your configuration data is never transmitted to any external server.