JSON formatter and validator
Check a complete JSON value, indent it with two or four spaces, or create a compact version. This tool uses your browser and does not upload the text.
How to use the formatter
- Paste one complete JSON value. Objects, arrays, strings, numbers, booleans and null are supported.
- Choose two-space or four-space indentation, or select compact output.
- If validation reports an error, correct the input and run it again. Copy or download the result.
Example
The value {"name":"Ana","active":true} can be indented or compacted without changing its data.
Limits and important details
- The input is limited to one million characters and 100 levels of nesting.
- Comments, trailing commas and JavaScript expressions are not valid JSON.
- Integers outside JavaScript safe precision are rejected to avoid silently changing values; store long identifiers as quoted strings.
Processing and privacy
The input is processed in this browser. The tool does not send your text or files to the server. Site code and fonts are loaded over the normal connection to ConverteArq. Close or reload the page and run the formatter again to recreate the result.
Frequently asked questions
Does this convert JavaScript objects into JSON?
It formats valid JSON text. It does not evaluate JavaScript expressions or comments.
Why was a large integer rejected?
JavaScript numbers cannot represent every large integer exactly. Use a quoted string for an identifier that must remain unchanged.
Is my input uploaded?
No. Formatting and validation run in your browser.