TOML to JSON/YAML Converter
Converts freely between any pair of TOML, JSON, and YAML. Handy for checking a TOML config file such as Cargo.toml or pyproject.toml as JSON or YAML. For JSON⇔YAML only, also try the YAML to JSON Converter, and if you want to further format or validate the resulting JSON, try the JSON Formatter tool.
🔒 Runs in your browser · Your data is never sent to a server
Notes
- TOML requires its top level to be a table (object). JSON or YAML whose top level is an array, string, or other non-object value cannot be converted to TOML.
- TOML has no equivalent of
null. Anullfield in JSON/YAML is dropped when converting to TOML. - Choosing the same format for both "from" and "to" reformats the document in place (e.g. TOML→TOML normalizes indentation and spacing).
- Everything runs entirely in your browser — the data you enter is never sent to a server.
Glossary
TOML
Short for Tom's Obvious, Minimal Language — a simple data format for writing config as `key = value` pairs. Widely used for package config files such as Rust's `Cargo.toml` and Python's `pyproject.toml`.
YAML
A human-friendly data format that represents structure through indentation. Widely used for config files such as Docker Compose, GitHub Actions, and Kubernetes manifests.
JSON
Short for JavaScript Object Notation — a text format that represents data as key/value pairs. Used everywhere from API payloads to config files.
Table
TOML's equivalent of a nested object. A header in square brackets, such as `[address]`, marks every `key = value` line that follows as belonging to that table.
FAQ
Can a top-level JSON array be converted to TOML?
No. TOML requires the top level to be a table (object), so JSON or YAML with a top-level array or string cannot be converted.
What happens to null values?
TOML has no null, so fields with null values in JSON or YAML are dropped in TOML output.
What happens if I pick the same format for input and output?
The content is reformatted in that format, for example TOML to TOML to normalize indentation and spacing.
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