Why did my comments disappear?

The TOML is generated from the parsed values. Comments have nowhere to go, and the page says so when it sees them.

Will a YAML timestamp become a TOML datetime?

No. The YAML 1.2 core schema reads it as a string, and the TOML output keeps that string.

No. Parsing and conversion happen in your browser.

Paste one YAML document. Comments are dropped, and null is an error.

Comments in the YAML are discarded. TOML has no null, and timestamps stay strings under the YAML 1.2 core schema.

Ctrl+Enter or ⌘+Enter runs this tool immediately.

YAML input

TOML output

Waiting for input.

Parsing stays in this browser. Input is not uploaded or saved.

Paste one YAML document, or load the sample.
If the status reports a comment, the comment is not in the TOML.
Copy or download only when the conversion succeeds. A failed parse leaves the output empty.

One YAML document only. A stream separated by --- is rejected.
Parsing uses the YAML 1.2 core schema. yes, no, on, and off stay strings. true and false are booleans.
Timestamps stay strings. The core schema does not turn them into TOML datetimes.
Null is rejected. Non-finite numbers and integers outside ±(2^53 − 1) are rejected.
Duplicate keys are errors. Merge keys written as << are not expanded.
Comments are discarded. Arrays must contain one kind of value.

A nested YAML mapping becomes a TOML table.

database:
  host: localhost
  port: 5432

Under the core schema, 2024-01-15 is a string, not a TOML date.

shipped: 2024-01-15

TOML has no null: Remove the null key or give it a string, number, or boolean.
More than one YAML document: Delete the extra --- documents and convert one table at a time.
Duplicate key: Keep one spelling of the key. The converter does not choose a winner.

Why did my comments disappear?: The TOML is generated from the parsed values. Comments have nowhere to go, and the page says so when it sees them.
Will a YAML timestamp become a TOML datetime?: No. The YAML 1.2 core schema reads it as a string, and the TOML output keeps that string.
Is the YAML uploaded?: No. Parsing and conversion happen in your browser.

TOML to YAML converter
Convert TOML 1.1 configuration to YAML with 2-space or 4-space indentation. Dates become strings, comments are dropped, and invalid TOML produces no YAML.
YAML to JSON converter
Convert YAML configuration to readable or compact JSON in the browser. Comments are dropped, and parse errors include line and column when the parser reports them.
JSON to TOML converter
Convert a JSON object to TOML in the browser. Null values and mixed arrays are rejected, and invalid JSON produces no TOML.