json2toon.co

YAML to TOML Converter

Input YAML

Output TOML

Your TOML appears here as you type.

Paste data to see token savings

Transform YAML to TOML for Python projects using modern config formats.

Example: YAML input and real TOML output

The output below was generated by the same conversion code the converter uses, run on this sample when the page was built.

YAML input (207 characters)
service:
  name: checkout-api
  image: registry.example.com/checkout:2.4.1
  replicas: 3
env:
  LOG_LEVEL: info
  DB_POOL_SIZE: 10
ports:
  - 8080
  - 9090
healthcheck:
  path: /healthz
  intervalSeconds: 15
TOML output (212 characters)
ports = [ 8080, 9090 ]

[service]
name = "checkout-api"
image = "registry.example.com/checkout:2.4.1"
replicas = 3

[env]
LOG_LEVEL = "info"
DB_POOL_SIZE = 10

[healthcheck]
path = "/healthz"
intervalSeconds = 15

TOML output is 2% larger than the YAML input. The same data is 214 characters as minified JSON and 295 as pretty-printed JSON. Sizes are character counts, not tokens: token counts depend on the model's tokenizer (see the tokenizer comparison).

YAML to TOML: what changes

  • Top-level scalars and arrays (ports) are written before any [table] header, as TOML requires. Each YAML mapping becomes a [table].
  • Reading YAML: Comments are dropped and anchors/aliases are expanded into copies. Unquoted values such as 2021 or 1.0 are read as numbers; quote them in the YAML if they must stay strings.
  • Writing TOML: TOML requires a top-level table: a root-level array is wrapped as [[data]]. Arrays of objects become [[name]] array-of-tables blocks, and null values are silently dropped because TOML has no null.

About YAML

YAML is a human-friendly data serialization format. It uses indentation instead of brackets, making configuration files more readable.

  • ✓Human readable
  • ✓No punctuation
  • ✓Supports comments
  • ✓Great for config
Full YAML Documentation →

About TOML

TOML is a config file format with explicit types. It's the official format for Python's pyproject.toml and Cargo's Cargo.toml.

  • ✓Explicit types
  • ✓Standard in Python/Rust
  • ✓Unambiguous
  • ✓Easy to parse
Full TOML Documentation →

Why Convert YAML to TOML?

Use TOML for application configuration, especially in Python (pyproject.toml) or Rust (Cargo.toml) projects. It has explicit types and no ambiguity.

YAML to TOML: Frequently Asked Questions

How do I convert YAML to TOML?

Paste your YAML into the editor on json2toon.co. The tool detects the input and produces TOML instantly, then you copy the result. Conversion runs entirely in your browser, so nothing is uploaded to a server.

Is the YAML to TOML converter free?

Yes. Converting YAML to TOML on json2toon.co is free with no account, signup, or usage limit. A free public API is also available for automated, programmatic conversion.

Why convert YAML to TOML?

Transform YAML to TOML for Python projects using modern config formats.

What should I watch out for when converting YAML to TOML?

Top-level scalars and arrays (ports) are written before any [table] header, as TOML requires. Each YAML mapping becomes a [table].

Is my data safe when I convert YAML to TOML?

Yes. The YAML to TOML conversion happens client-side in your browser. Your source data stays on your device and is never sent to or stored on a server, which makes it safe for private or sensitive payloads.