TOML (config)
Also known as: .toml file, Toms Obvious Minimal Language, toml config
TOML (.toml) is a human-readable configuration file format built around simple key = value lines grouped into [sections]. It is designed to be easy to read and write by hand, and is common in developer tooling for project and app settings.
- Human-readable config built on key = value lines
- Groups settings into [section] tables
- Common in developer tools like Cargo.toml and pyproject.toml
What TOML is for
TOML — "Tom’s Obvious, Minimal Language" — is a config format, not a data-exchange format. Its goal is an unambiguous file a person can edit in any text editor without tripping over punctuation, so it favors plain `key = value` lines over the brackets and quotes of JSON.
You will see TOML in developer settings files such as a Python project’s `pyproject.toml` or a Rust project’s `Cargo.toml`, where it lists dependencies and build options.
How it compares
Compared with INI, TOML adds clear data types (dates, numbers, arrays) and nested tables. Compared with YAML, it avoids significant indentation, which makes errors less surprising. Compared with JSON, it allows comments and is friendlier to edit by hand.
A .toml file is plain text, so it is tiny and safe to read. It is a configuration file, not personal data — leave it alone unless you maintain the project it belongs to.