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About this tool
Convert JSON into readable TOML with proper [table] sections, [[array of table]] syntax and safely quoted keys.
This converter serializes JSON into idiomatic TOML v1.0.0 — nested objects become [table] headers, arrays of objects become [[array of tables]] blocks, and keys outside the bare-key alphabet are emitted as quoted keys with correct escaping. Because TOML has no null, the tool makes null handling explicit: omit the key with a report, or fail the conversion. It is built for developers moving app config from JSON into TOML files such as pyproject.toml, Cargo.toml or netlify.toml.
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Nested objects become [table] sections and arrays of objects become [[array of tables]], not one giant inline blob.
Keys with spaces, dots or unicode are emitted as quoted basic-string keys per the TOML spec.
TOML has no null, so nulls are either omitted with a count or rejected — never silently mangled.
You cannot — the TOML specification has no null value, which is why this converter asks you to choose between omitting null keys and failing the conversion. The idiomatic TOML approach is to leave the key out entirely and treat absence as null in application code.
Because a TOML document is itself a table (a set of key/value pairs), so a top-level JSON array or bare scalar has no TOML equivalent. Wrap a root array in an object first, for example {"items": [...]}, and it will convert as an array or an array of tables.
Each object becomes one [[name]] block — TOML's array-of-tables syntax — so "products": [{...}, {...}] turns into two [[products]] sections. An object inside a mixed array (one that also holds numbers or strings) is emitted as a single-line inline table instead, because the spec only allows array-of-tables syntax when the whole array is objects.
Whenever it contains anything beyond ASCII letters, digits, underscore and dash — the only characters allowed in a bare key. This converter automatically writes such keys as quoted basic strings, so "my key.v2" = 1 comes out valid rather than breaking the file.
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