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 anchors are resolved on read.

FAQ

Related tools

• YAML to JSON
• JSON to TOML
• TOML to JSON
• TOML to YAML