About this conversion
Convert TOML to JSON when you need to feed Rust/Python config data into a JavaScript or web context. JS doesn't read TOML natively, but every JS tool reads JSON — so the conversion is the standard bridge for embedding TOML configs into a webapp or API client.
When this conversion is useful
- Embedding TOML config (Cargo, pyproject) into a JavaScript build tool
- Validating a TOML file against a JSON schema
- Producing JSON snapshots of TOML configs for monitoring or diffing
- Interoperating between Rust/Python and JS toolchains
Quality and tradeoffs
Tables become objects, arrays become arrays. TOML's typed dates round-trip as ISO 8601 strings (JSON has no date type). Inline tables and arrays-of-tables are flattened correctly. Comments are dropped — JSON has no comment syntax.
Frequently asked questions
How are TOML dates represented in JSON?
As ISO 8601 strings. JSON has no native date type, so the date semantics are preserved in the format but parsing it back into a typed value is up to the consumer.
Are comments preserved?
No — JSON has no comment syntax, so TOML comments are dropped. To preserve them, keep the TOML as source-of-truth and generate JSON as a build step.
What about TOML's arrays-of-tables?
They become arrays of objects in JSON, exactly as you'd expect. `[[products]]` blocks turn into `"products": [ { … }, { … } ]`.