TOML Validator & Formatter
About TOML Validator / Formatter
TOML Validator / Formatter parses configuration against the TOML grammar before producing a consistent representation of keys, values, tables and arrays of tables.
How it works
Specification-focused parsing
The parser covers modern TOML strings, numbers, dates and times, dotted keys, inline tables, arrays and arrays of tables. Syntax failures include source line and column details.
Deterministic serialization
Valid data is serialized with normalized spaces, array punctuation and table sections. Recursive key sorting is optional so source insertion order can remain meaningful.
Numeric control
Large integers are parsed without losing precision. The float option can force JavaScript numbers to include floating-point notation when a consumer distinguishes integer and float types.
Frequently asked questions
Are comments preserved?
No. The formatter serializes the parsed data model, so comments and exact source spelling are not retained.
Does this improve the TOML converters too?
Yes. TOML parsing and serialization are shared with the TOML-to-JSON, YAML and related configuration tools.
Can JSON null become TOML?
No. TOML has no null value, and converters report the incompatible path rather than dropping it.
Sources & last verified
The behaviour of this tool and the claims on this page were checked against the specifications below on . Everything runs in your browser, so the output you see is exactly what the engine produced.
Found a wrong result or an outdated claim? Report an error and it will be re-verified.