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About this tool
Convert TOML config files to JSON in the browser — tables, arrays of tables, dotted keys and dates handled per TOML 1.0.
This converter parses TOML v1.0.0 — tables, arrays of tables, dotted keys, inline tables, multi-line strings and RFC 3339 date-times — and emits clean RFC 8259 JSON, entirely in your browser. Duplicate keys and redefined tables are rejected exactly as the TOML spec demands, so a file that converts here is a file a strict parser will accept. It is built for developers who need Cargo.toml, pyproject.toml, netlify.toml or any app config as JSON for scripts, APIs or schema validation.
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Duplicate keys, redefined tables and invalid escapes fail with the line number, per TOML v1.0.0.
Dotted keys, inline tables, hex/octal/binary integers, underscored numbers and multi-line strings all convert.
Date-times become strings and inf/nan become null, with a note for every substitution JSON forces.
Each [[name]] header appends one object to a JSON array under that key, so two [[products]] blocks become "products": [ {...}, {...} ]. Sub-tables declared between the headers, such as [products.details], attach to the most recent element, and this converter follows that TOML v1.0.0 rule.
They become plain strings, because JSON has no date type. TOML's four RFC 3339 shapes — offset date-time, local date-time, local date and local time — are all preserved character-for-character (for example 1979-05-27T07:32:00Z), and the tool reports how many were converted.
Because the TOML specification makes redefining a key or table a hard error, not a warning — the second definition does not silently win as it does in some INI parsers. Check the reported line: the same key may be set once as a dotted key and again inside a [table] header covering the same path.
Yes. Hexadecimal (0x), octal (0o) and binary (0b) integers and underscore-separated numbers are parsed to their numeric values, so 0xFF becomes 255 and 1_000_000 becomes 1000000 in the JSON output. Decimal integers with leading zeros are rejected, as the spec requires.
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