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 TOML to JSON
TOML is the configuration language of choice for Rust (Cargo.toml), Python packaging (pyproject.toml), Hugo static sites, and a growing number of developer tools. But when you need to process TOML data programmatically, integrate with JSON-based APIs, or use tools that only accept JSON input, you need a reliable TOML to JSON converter. This free online tool transforms TOML into valid JSON instantly in your browser.
Why Convert TOML to JSON?
While TOML excels as a human-readable configuration format, JSON is the universal data interchange language. Converting TOML to JSON is necessary when building tools that process Cargo.toml or pyproject.toml files, integrating TOML-based configurations with JSON APIs, migrating projects between different configuration formats, or debugging complex TOML files by viewing their resolved JSON structure. JSON's explicit syntax can make it easier to verify that a TOML file is being parsed as intended.
The Rust ecosystem, in particular, uses TOML extensively for Cargo.toml package manifests, workspace configurations, and build profiles. Converting these to JSON enables programmatic analysis — checking dependency versions, extracting metadata for CI/CD pipelines, or feeding configuration data into JavaScript-based tools.
Common Use Cases
- Rust projects: Parse Cargo.toml into JSON for dependency analysis, version checking, and CI/CD automation scripts.
- Python packaging: Convert pyproject.toml to JSON for tooling that processes Python project metadata and build configurations.
- Hugo sites: Transform Hugo config.toml into JSON for programmatic site configuration and theme development.
- Configuration migration: Move from TOML-based configs to JSON-based alternatives when changing tools or frameworks.
- Debugging: Visualize the resolved structure of complex TOML files with nested tables and arrays of tables in JSON format.
- API integration: Feed TOML configuration data into REST APIs and webhooks that accept JSON payloads.
TOML Features Supported
This converter supports the full TOML v1.0 specification including standard tables [table], arrays of tables [[array]], inline tables, dotted keys (a.b.c = value), basic and literal strings, multiline strings, integers in decimal/hex/octal/binary, floats including inf and nan, booleans, offset date-times, local date-times, local dates, and local times. Comments are preserved in the TOML input but naturally excluded from JSON output since JSON does not support comments.
Privacy First
This TOML to JSON converter runs entirely in your browser. Your configuration files, Cargo.toml manifests, and project metadata never leave your device — no API calls, no server processing, no data retention. Safe for private projects and internal tooling.