TOML ↔ JSON/YAML Converter
Convert between TOML, JSON, and YAML formats. Perfect for Cargo.toml, pyproject.toml, and configuration files.
About TOML ↔ JSON/YAML Conversion
- TOML (Tom's Obvious Minimal Language) — simple config format used by Cargo (Rust), pyproject.toml (Python), Hugo, and many CLI tools.
- JSON — strict key-value format for APIs, data exchange, and tooling configs like package.json and tsconfig.json.
- YAML — indentation-based format popular for Kubernetes, Docker Compose, and CI/CD pipelines.
- TOML requires a table (object) at the root — arrays and primitives are not valid top-level values.
- Everything runs in your browser — no data is sent over the network.
How to Convert JSON to TOML
TOML is gaining rapid adoption as the configuration format for Rust (Cargo.toml), Python (pyproject.toml), Hugo, Deno, and many modern developer tools. If you have data or configuration in JSON format and need to convert it to TOML, this free online converter handles the transformation instantly in your browser — generating clean TOML with proper table sections, arrays, and type-appropriate formatting.
Why Convert JSON to TOML?
TOML offers significant advantages over JSON for configuration files. It supports inline comments, which are essential for documenting configuration choices. Its table-based syntax is more readable than deeply nested JSON braces. TOML has native date/time types, eliminates the trailing comma problem, and never requires quoting simple string values. Converting JSON configurations to TOML makes them more maintainable for teams that hand-edit config files.
Common scenarios include bootstrapping a new Rust project by converting a package.json structure to Cargo.toml, migrating Python project metadata from setup.cfg or setup.py (via JSON) to pyproject.toml, generating Hugo site configurations from templates, or converting CI/CD pipeline data into TOML-based configuration files.
Common Use Cases
- Rust development: Generate Cargo.toml package manifests from JSON templates or API responses containing package metadata.
- Python packaging: Create pyproject.toml files from JSON-structured project metadata for Poetry, PDM, or Hatch.
- Static sites: Convert JSON config data into Hugo config.toml or other TOML-based static site generator configurations.
- Configuration migration: Move from JSON-based configs (e.g., tsconfig.json, package.json patterns) to TOML for projects that prefer TOML.
- Template generation: Convert JSON schemas or templates into TOML configuration file templates for distribution.
- Tooling automation: Generate TOML configs programmatically from JSON data in CI/CD pipelines and build scripts.
How JSON Maps to TOML
JSON objects become TOML tables: a top-level key-value pair stays at the root, while nested objects become [table] sections. JSON arrays of objects become TOML arrays of tables ([[table]]). Scalar values map directly — JSON strings become TOML strings, numbers become TOML integers or floats, and booleans map to TOML true/false. JSON null values are handled as empty strings since TOML does not have a null type. The converter produces clean, idiomatic TOML that follows community conventions.
Privacy First
This JSON to TOML converter runs entirely in your browser. Your data and configuration files never leave your device — no API calls, no server processing, no data retention. Safe for private project configurations, API keys in test configs, and internal tooling metadata.