TOML to JSON Converter
TOML Input
JSON Output
About TOML to JSON Converter
Convert TOML configuration files to JSON format instantly. TOML (Tom's Obvious Minimal Language) is widely used in Rust projects (Cargo.toml), Python packaging (pyproject.toml), Hugo static sites, and modern build tools. This tool parses TOML files and converts them to JSON, making it easy to work with TOML data in APIs, databases, and JavaScript applications. The parser handles tables (sections), nested tables, arrays, inline tables, strings, numbers, booleans, and comments. TOML's simple key-value syntax with sections makes it ideal for configuration files, and converting to JSON allows you to use this data programmatically. Perfect for processing Cargo.toml or pyproject.toml files, converting TOML configs for APIs, working with TOML data in JavaScript, or integrating TOML-based tools with JSON systems. All conversion happens in your browser for complete privacy.
How to Use
- Paste or type your TOML data in the left panel.
- The JSON output will appear automatically on the right.
- Choose your preferred JSON indent size (2 or 4 spaces).
- Click "Copy" to copy the JSON to your clipboard.
- Click "Download" to save the JSON as a .json file.
- Use "Clear" to reset both input and output.
- The tool supports tables, arrays, inline tables, and all TOML data types.
Frequently Asked Questions
What TOML features are supported?
This tool supports the most common TOML features: tables [section], nested tables [parent.child], key-value pairs, arrays [...], inline tables {...}, strings (quoted and unquoted), integers, floats, booleans (true/false), and comments (#). Most standard TOML files will convert perfectly.
Why would I convert TOML to JSON?
Common use cases include: processing Cargo.toml or pyproject.toml programmatically, using TOML configs with REST APIs (which expect JSON), working with TOML data in JavaScript/Node.js applications, converting configuration files for databases, validating or debugging TOML files, and integrating TOML-based tools with JSON-based systems.
Does this support all TOML specifications?
This tool supports TOML v1.0 core features that cover 99% of real-world usage. Advanced features like datetime types, multi-line literal strings (with special quotes), and some exotic array-of-tables syntax may have limited support. For most config files (Cargo.toml, pyproject.toml), this works perfectly.
What happens to TOML comments?
Comments (lines starting with #) are ignored during parsing and won't appear in the JSON output. JSON doesn't support comments, so they cannot be preserved during conversion.
How are TOML tables converted?
TOML tables (sections like [database]) become nested JSON objects. Dotted table names like [database.connection] create nested objects: {"database": {"connection": {...}}}. This preserves the hierarchical structure of your TOML file.
Can I convert Cargo.toml or pyproject.toml files?
Yes! This tool works great for Rust's Cargo.toml and Python's pyproject.toml files. These are standard TOML files, and converting them to JSON lets you process package metadata, dependencies, and build configurations programmatically.
What if my TOML has syntax errors?
The tool will display an error message if it cannot parse your TOML. Common issues include missing quotes around strings with special characters, incorrect table syntax, missing equals signs in key-value pairs, or mismatched brackets. Fix the syntax error and the conversion will work automatically.
Can I convert JSON back to TOML?
Yes! Use our JSON to TOML converter tool to convert in the opposite direction. You'll find it in the Code Conversion Tools section.
Is my data secure?
Absolutely! All conversion happens entirely in your browser using JavaScript. Your TOML data never leaves your computer and is not sent to any server. You can even use this tool offline once loaded.
Why use TOML over JSON or YAML?
TOML is designed specifically for configuration files. It's more readable than JSON (less syntax clutter), simpler than YAML (no indentation ambiguity), has clear unambiguous types, supports comments, and is perfect for configs where humans need to read and edit frequently. It's the standard for Rust and Python projects.