TOML to JSON Converter

TOML (Tom's Obvious Minimal Language) is a configuration file format designed to be easy to read and write. It uses a simple key-value syntax with support for strings, integers, floats, booleans, datetimes, arrays, and tables (objects). It was created by Tom Preston-Werner, a co-founder of GitHub.

TOML is more readable than JSON for config files because it does not require quotes around keys and uses human-friendly syntax for sections and arrays. Compared to YAML, TOML has fewer edge cases and surprises. TOML is better suited for configuration files. JSON is better for data interchange. YAML is common in DevOps tooling like Kubernetes and Ansible.

TOML is the configuration format for Rust projects (Cargo.toml), Python projects (pyproject.toml with Poetry or Hatch), the Hugo static site generator, the Zola static site generator, and many CLI tools. It is also the default config format for the uv Python package manager.

Yes. TOML has native date, time, and datetime types. For example: published = 2026-03-16T10:30:00Z. When converting to JSON, these are serialized as ISO 8601 strings since JSON has no native date type.

Each [[products]] header adds one object to an array called products. Two [[products]] blocks with a name key become "products": [{"name": "a"}, {"name": "b"}] in JSON. Single bracket [server] headers become nested objects instead, so [server] with port = 8080 becomes "server": {"port": 8080}.

The parser follows the TOML spec strictly. The most common errors are a key defined twice in the same table, a [table] header repeated, an unquoted string value, and an integer too large to represent exactly in JSON (above 9007199254740991). The parser rejects that last case with an error rather than silently rounding the number, so quote the value as a string if you need it preserved.