Free YAML to TOML Converter — convert YAML config to TOML in your browser

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🔄 YAML to TOML — Free Online Tool

Convert YAML to TOML online, free. YAML is an indentation-based superset of JSON favoured for human-edited config. TOML is a readable configuration format built around key/value pairs and tables. YAML to TOML conversion parses your YAML against the YAML 1.2.2 grammar (https://yaml.org/spec/1.2.2/), builds an in-memory model of its keys, nested objects and arrays, then re-serializes it as valid TOML following the TOML v1.0.0 conventions. Processing runs in your browser in JavaScript with no upload or server round-trip — no size limit beyond your device's memory, so multi-megabyte documents convert in milliseconds and sensitive payloads never leave your machine. Typical uses include Rust Cargo & Python pyproject config, app settings files and tool configuration.

🚀 Why use this YAML to TOML tool?

It maps the full structure of your YAML onto well-formed TOML, following the TOML v1.0.0 conventions. 100% free, no registration, and complete privacy — everything runs locally in your browser, so your data never touches a server.

Key Features

Instant, in-browser

Paste YAML and convert TOML immediately. Conversion runs client-side, so there is no upload wait and large documents stay fast.

🧩Structure-aware mapping

Nested YAML objects, tables and arrays are mapped faithfully onto TOML.

🔒100% private

Your YAML never leaves your device — everything is processed locally in JavaScript, with nothing logged or stored.

🆓Free, no signup

Unlimited conversions with no account, no quotas, and no watermark. Works on desktop and mobile.

Popular Use Cases

TOML pipelines

  • Move YAML data into TOML-only tools
  • Rust Cargo & Python pyproject config
  • app settings files

Where TOML is used

  • Rust Cargo & Python pyproject config
  • app settings files
  • tool configuration

Quick one-off conversion

  • Paste YAML, copy TOML
  • No install or CLI needed
  • Repeatable and shareable

What It Handles

Structure

  • Nested objects & tables
  • Arrays / lists
  • Deeply nested documents

Values

  • Strings, numbers, booleans
  • Dates where supported
  • Null / empty handling

Workflow

  • Copy or download output
  • Load an example to try it
  • Validate & format the input

Worked example

A YAML document and its TOML equivalent:

YAML input:

name: Alice
age: 30
email: [email protected]

Output:

name = "Alice"
age = 30
email = "[email protected]"

Sources & References

Frequently Asked Questions

How do I convert YAML to TOML?

Paste your YAML into the editor and press "Convert to TOML". The tool parses it against the YAML 1.2.2 grammar, then re-serializes it as TOML following TOML v1.0.0 conventions — instantly and entirely in your browser. You can validate or format the YAML first to be sure it is clean.

How is YAML structure represented in TOML?

YAML anchors and aliases are expanded and comments are dropped before TOML is produced, and indentation defines the structure. Note that YAML 1.1 treats words like "yes" and "no" as booleans, so quote them if you want strings.

Does converting YAML to TOML preserve data types?

Numbers, booleans and null are preserved as native TOML types wherever TOML supports them, so standard documents convert losslessly and can be read back into the same structure.

What is the difference between YAML and TOML?

YAML (YAML Ain't Markup Language) (YAML) — YAML is an indentation-based superset of JSON favoured for human-edited config. TOML (Tom's Obvious Minimal Language) (TOML) — TOML is a readable configuration format built around key/value pairs and tables. This converter maps the structure of your YAML onto TOML so you can use it for Rust Cargo & Python pyproject config.

Does the converter validate my YAML first?

Yes. Invalid YAML is flagged with a clear error before anything is converted. Common YAML problems to check are spaces (never tabs) for indentation, consistent indent levels, and no duplicate keys. Starting from clean input keeps the generated TOML accurate.

Is my YAML data private?

Yes. The entire YAML-to-TOML conversion runs locally in your browser in JavaScript — your YAML is never uploaded, logged or stored. That matters when the data is something like Kubernetes & Docker Compose manifests, which should not leave your machine.

Where can I use the TOML output?

The generated TOML is ready for Rust Cargo & Python pyproject config, app settings files and tool configuration. Copy or download it and drop it straight into your tooling.

🎓 Pro Tips

  • Tip 1: Validate or format your YAML first (the Validate / Format buttons) so the converter works from clean, YAML 1.2.2-conformant input.
  • Tip 2: Keep an eye on type coercion: YAML and TOML don't always represent numbers, dates and nulls the same way.
  • Tip 3: Authoritative reference for the input format: YAML 1.2.2 — https://yaml.org/spec/1.2.2/.
  • Tip 4: For the output, follow the TOML v1.0.0 (https://toml.io/en/v1.0.0) conventions in your codebase.