TOML → JSON
Converter

About the TOML ↔ JSON Converter

TOML (Tom's Obvious Minimal Language) is the configuration format used by Rust's Cargo.toml, Python's pyproject.toml, Hugo, Zola, and many Go projects. This free online converter translates between TOML and JSON in both directions, handling tables, dotted keys, inline tables, and arrays of tables. Everything runs in your browser.

Supported Syntax

• Basic key/value pairs: strings, numbers, booleans, dates (as strings)
• Numeric formats: decimal, hex (0x), octal (0o), binary (0b)
• Underscores in numbers: 1_000_000
• Standard tables: [database.primary]
• Inline tables: point = { x = 1, y = 2 }
• Arrays of tables: [[servers]] (becomes a JSON array of objects)
• Dotted keys: a.b.c = 1
• Line comments with #

Why Projects Chose TOML

TOML was designed to be unambiguous and friendly to humans editing it by hand. Unlike YAML, it has no indentation significance and no "Norway problem" — country = "NO" stays a string. Unlike JSON, it allows comments and multi-line strings.

Common Use Cases

• Convert Cargo.toml to JSON for CI pipelines or dashboards
• Inspect pyproject.toml dependencies programmatically
• Migrate Hugo/Zola site configs between TOML and JSON
• Share settings between tools that speak only one format

Frequently Asked Questions

Does the converter support TOML 1.0 completely?

It supports the common 95% of TOML 1.0: tables, dotted keys, inline tables, arrays of tables, numeric literals with underscores, hex/octal/binary ints, and standard escape sequences in basic strings. Multi-line triple-quoted strings and offset date-times are passed through as strings.

How are datetimes handled?

TOML datetimes have no direct JSON representation, so they are preserved as ISO 8601 strings on both sides of the conversion. Date parsing in your target language can take over from there.

Is my config sent to a server?

No. Parsing and emitting both happen in your browser — safe for config files containing API keys, database credentials, or private tokens.

Related Tools

Convert the same data to YAML, CSV, or XML. Learn when to pick each format in the JSON vs YAML guide.