Compare
JSON vs TOML
JSON is widely used for APIs and program-to-program data exchange. TOML is designed for human-edited application configuration, with readable keys, values, tables, and arrays.
Which format should you choose?
Use JSON when an API or tool expects it. Consider TOML for maintained configuration that benefits from comments and clear tables, after checking parser and version support.
Good fit for JSON
Web APIs, configuration files, and data exchange
- Transferring structured data
Good fit for TOML
Application and tool configuration
- Readable settings with structured values
Basic information
| Field | JSON | TOML |
|---|---|---|
| Extension | .json | .toml |
| MIME type | application/json | application/toml |
| Common uses | Web APIs, configuration files, and data exchange | Application and tool configuration |
| How to open | Open it in a text editor, IDE, or JSON-aware viewer. | Open it in a text editor or configuration-aware editor. Check the application's documentation for supported TOML features. |
| Export or convert | Applications or conversion tools can convert it to formats such as CSV. | When converting from JSON or YAML, verify nesting, arrays, string quoting, dates, and value types after parsing. |
Choose by use case
Transferring structured data
Web APIs, configuration files, and data exchange
JSONReadable settings with structured values
Application and tool configuration
TOMLKey point 1
JSON is standardized for structured data interchange and does not include comments in its standard syntax.
More on the differencesKey point 2
TOML is a text format for configuration, with tables and arrays intended to be readable and editable.
More on the differencesMore on the differences
Choose the format supported by the receiving application and workflow. Validate the schema and check that values such as dates, numbers, and arrays retain their intended types during conversion.
- JSON is common in APIs and interoperable machine exchange.
- TOML can make hand-maintained settings clearer, but is not accepted by every JSON-oriented service.
- Both require parser and schema validation when configuration affects application behavior.
Frequently asked questions
Should configuration always use TOML instead of JSON?
No. Use the format required by the toolchain; TOML can be convenient for human-edited settings, while many APIs and tools require JSON.
Can JSON include comments?
Standard JSON does not support comments. If comments are required, use a format and parser that explicitly allow them.