TOML ↔ JSON Converter
LiveConvert TOML to JSON and JSON to TOML bidirectionally online.
Understanding JSON (JavaScript Object Notation)
TOML (Tom's Obvious Minimal Language) is a configuration file format designed for readability — used by Rust (Cargo.toml), Python (pyproject.toml), Hugo, and other projects. TOML uses sections ([table]), key-value pairs (key = "value"), and inline tables for structured configuration. Converting between TOML and JSON is necessary when tools accept one format but your configuration exists in the other, when migrating between build systems, or when programmatically generating configuration from JSON-based templates.
Use this free TOML to JSON converter to transform TOML configuration files to JSON and vice versa. Supports the full TOML spec including tables, arrays of tables, inline tables, multiline strings, dates, and dotted keys. Essential for working with Rust (Cargo.toml), Python (pyproject.toml), Go, and other ecosystems that use TOML configuration files.
The Devkitr TOML/JSON Converter transforms between TOML and JSON formats bidirectionally. Paste TOML to get JSON or paste JSON to get TOML — with proper handling of TOML tables, array-of-tables, inline tables, date-time values, and multi-line strings.
In a typical development workflow, TOML ↔ JSON Converter becomes valuable whenever you need to convert toml to json and json to toml bidirectionally online. Whether you are working on a personal side project, maintaining production applications for a company, or collaborating with a distributed team across time zones, having a reliable browser-based conversion tool eliminates the need to install desktop software, write one-off scripts, or send data to third-party services that may log or retain your information. Since TOML ↔ JSON Converter processes everything locally on your device, your data stays private and your workflow stays uninterrupted — open a browser tab, paste your input, get your result.
Key Features
Bidirectional Conversion
Converts TOML to JSON and JSON to TOML in the same interface, supporting round-trip conversion between formats.
Table Section Handling
Maps TOML [section] and [[array-of-tables]] syntax to nested JSON objects and arrays of objects correctly.
TOML Date-Time Support
Handles TOML date-time values (2024-03-31T12:00:00Z), local dates, and local times with appropriate JSON string representation.
Comment Preservation Info
Notes which TOML comments were present in the input — since JSON cannot represent comments, they are listed separately.
How to Use TOML ↔ JSON Converter
Paste TOML or JSON
Enter TOML content (Cargo.toml, pyproject.toml) or JSON data to convert to the other format.
Select Direction
The tool auto-detects the input format, or manually select TOML→JSON or JSON→TOML.
Review Output
Check the converted output for correct table nesting, array handling, and data type preservation.
Copy Result
Copy the converted content for use in your project configuration, build system, or tooling.
Use Cases
Rust/Cargo Configuration
Convert Cargo.toml package configuration to JSON for programmatic analysis or convert JSON build templates to TOML for Rust projects.
Python Project Setup
Work with pyproject.toml configuration in JSON format for tooling that processes JSON, or generate pyproject.toml from JSON templates.
Hugo Site Configuration
Convert between Hugo's TOML, YAML, and JSON configuration formats when migrating sites or using different configuration tools.
Configuration Comparison
Convert TOML to JSON for comparison with other JSON-based configurations using JSON diff tools.
Pro Tips
TOML [[array-of-tables]] syntax represents arrays of objects — each [[section]] creates a new object in the array, not overwrites.
TOML distinguishes between integers and floats (42 vs 42.0) — JSON does not. Verify numeric types after conversion.
Use inline tables { key = "value" } in TOML for simple nested objects that would create overly verbose [section] blocks.
TOML comments (# comment) are lost in JSON conversion. Document important comments separately if converting permanently.
Common Pitfalls
Confusing [table] and [[array-of-tables]] TOML syntax
Fix: [package] creates an object. [[package]] creates an array of objects. Using the wrong one produces incorrect nesting in JSON.
Not handling TOML date-time values in JSON
Fix: TOML has native date-time types. JSON represents these as strings — ensure downstream JSON consumers parse the date strings correctly.
Assuming JSON key order matches TOML section order
Fix: JSON object key order is implementation-dependent. If order matters, use TOML as the authoritative format and treat JSON as a derived representation.
Frequently Asked Questions
QHow do I convert TOML to JSON?
Paste your TOML content and the converter instantly generates the equivalent JSON output. Supports all TOML features including tables, arrays, and dotted keys.
QIs the TOML to JSON conversion bidirectional?
Yes. Convert TOML → JSON or JSON → TOML by switching the mode toggle.
QDoes it work with Cargo.toml and pyproject.toml?
Yes. Fully compatible with Rust Cargo.toml, Python pyproject.toml, and any other standard TOML configuration files.
QWhich TOML features are supported?
Tables, arrays of tables, inline tables, dotted keys, multiline strings, integers, floats, booleans, and datetime values.
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