JSON / YAML / TOML Toolbox
Validate locally, format, and convert among JSON, YAML, TOML; supports recursive key sorting and unsafe conversion detection.
How to use the JSON / YAML / TOML toolbox
Text entered or configuration files are parsed and converted only in the current browser, and will not be uploaded.
Enter and recognize format
Paste content or load .json, .yaml, .yml, or .toml files up to 1 MiB; the source format can be detected automatically or specified manually.
Validate and organize
After parsing, check for errors and conversion warnings, then choose formatting or recursive key sorting.
Select target format
Convert among JSON, YAML, and TOML, and copy or download the result; before publishing, verify the semantics of comments, dates, and numeric values.
Limitations and Notes
- Conversion removes comments, YAML anchors will be expanded; explicit tags, TAG, circular references, and keys related to prototype pollution will be blocked.
- Non-safe integers, types that the target format cannot represent losslessly, and conversion of TOML dates to JSON or YAML will be blocked instead of silently changing the value.
- The input can be up to 1 MiB, with a single line up to 100000 characters, 100 levels of nesting, and 100000 nodes; different implementations may still differ on the boundary syntax for YAML or TOML.
FAQ
Why did the comments disappear after conversion?
The parser first builds the data structure and then serializes it. Comments are not part of the generic data model, so the tool will explicitly warn you but cannot preserve them.
Why can’t the TOML date be converted to JSON?
Direct conversion may silently turn typed dates into ordinary strings; the tool chooses blocking to avoid misinterpreting lossless semantics.
Will it execute YAML tags or construct arbitrary objects?
No. Explicit tags and dangerous keys will be rejected, and the tool accepts only restricted plain data structures.