Free YAML to TOML Converter Online
Convert YAML to TOML in your browser — free, instant, no data sent to servers.
YAML Input
TOML Output
What Is YAML to TOML?
You're migrating a project to Rust and need to convert your YAML config to a Cargo.toml, or you're setting up a pyproject.toml for Python. That's exactly what this tool does. TOML (Tom's Obvious Minimal Language) is more explicit than YAML — it uses [section] headers rather than indentation. Converting YAML to TOML maps keys to TOML tables and values per the TOML spec.
Your YAML is read into a data tree and then written back out as the equivalent TOML tables and key/value pairs. All of that happens in this browser tab, so the config never gets uploaded. Starting from JSON rather than YAML? Use JSON to TOML. The YAML spec and TOML spec define the formats.
YAML to TOML Examples
Convert YAML to TOML. Telecom-themed example:
Example: Subscriber record
TOML Output:
Click the Sample button above to load more examples into the editor.
How to Use This Tool
Paste or Upload YAML
Your YAML goes in the left pane; you can also open a .yaml or .yml file with Upload; Sample gives you a small subscriber config to experiment with. If the YAML cannot be parsed, you get an error message in place of TOML output.
View TOML Output
Converted TOML appears on the right. YAML keys become TOML keys; nested objects become [section] tables. Arrays become TOML arrays. Invalid YAML will show an error in the output.
Copy or Download
Use Copy or Download. For JSON to TOML, use JSON to TOML. For YAML formatting, use YAML Formatter.
When YAML to TOML Helps
When migrating config from YAML to a TOML-based project (e.g. Rust with Cargo, Python with Poetry), or when a tool expects pyproject.toml or Cargo.toml style config, this conversion helps. Kubernetes and Docker Compose use YAML; many language ecosystems use TOML. Converting here bridges the gap.
TOML is more explicit and has a stricter structure. Some prefer it for config because it's less ambiguous than YAML. If your source is YAML (e.g. from a shared config repo) but the target is TOML, paste it here. For JSON to TOML, use JSON to TOML.
Frequently Asked Questions
When to use TOML vs YAML?
TOML is used by Rust (Cargo), Python (Poetry), and many CLI tools. YAML is common in Kubernetes, Docker Compose, and CI/CD. Use this tool when you need to convert between them—e.g. sharing config across ecosystems.
Does TOML support nested tables?
Yes. TOML uses [section.subsection] for nesting. The converter maps YAML nesting to TOML table headers. Deep nesting is supported.
Does my YAML get uploaded during conversion?
No. The YAML is parsed and rewritten as TOML by the page itself, so your config stays on this machine.
What about YAML anchors?
YAML anchors and aliases are resolved during conversion. The output TOML contains the expanded structure. TOML has no equivalent for anchors.
Comments preserved?
TOML uses # for comments. YAML comments may not always map cleanly—the converter focuses on structure and data. Check the output and add comments if needed.
Related Tools
TOML. YAML spec. JSON spec. TOML GitHub. YAML quick reference.