YAML to TOML

YAML is the widespread configuration format for CI pipelines, Docker Compose, Kubernetes and many tools - using indentation instead of brackets and little ceremony. TOML pursues the same goal of human readability, but relies on sections in square brackets and plain key-equals-value lines, like a Cargo.toml or pyproject.toml uses. This tool reads your YAML file and writes the same structure as well-formed TOML.

The conversion runs entirely locally in your browser: js-yaml reads the YAML, smol-toml writes the TOML, both pure JavaScript. Nested mappings become TOML tables and sub-tables (such as [server.meta]), sequences become TOML arrays, timestamps become real date/time values. From an indented YAML configuration you get a clearly structured .toml that you can version and commit straight away.

This closes the gap between the formats: JSON to YAML, JSON to TOML and now YAML to TOML are all available locally. It stays honest about it: a TOML document needs a table at the top level, so a YAML sequence, a single scalar or null at the root is rejected with a clear message instead of failing cryptically. And because TOML has no null type, mappings with null values are reported, not silently dropped. Nothing is uploaded.

Specifications

In 3 steps

1. Drop or pick your YAML file.
2. The tool converts it into TOML.
3. Download the TOML file.

Limitations: Expects a YAML mapping at the top level; a sequence, scalar or null at the root is rejected with a clear message. Nested mappings become sub-tables, sequences become TOML arrays, timestamps become TOML date/time values. TOML has no null type, so mappings with null values are rejected instead of being silently dropped. YAML comments are lost, since TOML cannot represent them in the same place. YAML anchors are resolved on read.

FAQ

Related tools

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