Large numeric identifier
{"id":9007199254740993} converts without rounding the identifier through a JavaScript number.
106 / 500,000 characters. Processing stays in this browser.
Convert structured data
Long integer IDs and decimal fractions stay exact. JSON duplicate keys are rejected. YAML comments and anchors do not appear in JSON; aliases expand with limits. Only JSON-compatible YAML core values and string mapping keys are supported.
YAML 1.2 treats yes and no as strings. Dates stay strings. Merge keys are not applied. Infinity, NaN, custom tags, and cyclic aliases return visible errors.
All parsing and exports run locally in your browser. Example records are original fictional data, not an external dataset.
How to use the JSON / YAML Converter
- 01
Choose JSON to YAML or YAML to JSON.
- 02
Paste or load a single document and choose output indentation.
- 03
Convert, inspect the output, then copy, download, or reverse using that output.
Examples
A word that looks like a Boolean
In YAML 1.2, label: yes converts to {"label":"yes"}; enabled: true converts to a JSON Boolean.
Represent data without silently changing numbers
The converter traverses parsed syntax trees. JSON numbers retain their tokens; YAML integer and decimal spellings are normalized into valid JSON numeric tokens without floating-point arithmetic. This includes decimal fractions longer than typical machine precision. Your downstream application may still round large numbers when it reads the output.
Where the formats do not overlap
JSON has no comments, anchors, custom tags, or non-finite numeric values. Supported YAML aliases expand into ordinary values, comments disappear, and Infinity or NaN cause an error. Mapping keys must be string-compatible scalar keys; complex collection keys are refused. Duplicate keys are refused in either format.
Keep the reverse conversion in perspective
A data round trip does not preserve YAML formatting. Anchor names, scalar style, hexadecimal integer spelling, directives, and comments are normalized away. JSON duplicate-key documents cannot be converted. Merge keys remain ordinary strings, and no external resources or executable tags run.
What to know
- Input is limited to 500,000 characters. Review the supported syntax and export policy described above.
Common questions
Will my decimal money values be rounded?
The tool preserves numeric token precision. The application that consumes the result determines how those values are stored and calculated.
Can I convert several YAML documents together?
No. Convert one document at a time; multiple-document streams return an error.
Are files uploaded?
No. File reading and conversion happen in the browser. Copy and download are explicit actions.