Browser-only tool
JSON formatter and validator
Paste JSON to validate syntax, pretty-print it with indentation, or minify it for transport. Processing happens locally in the browser.
Waiting for input.
What This Tool Checks
The formatter parses JSON with the browser JavaScript runtime. Valid input can be printed with readable indentation or minified. Invalid input shows the parser error so you can find the syntax issue.
It validates JSON syntax, not application schemas or API contracts.
Privacy And Limitations
JSON input is parsed and formatted locally in your browser. This static page does not upload pasted data.
- Do not paste production secrets unless you trust the browser and local environment.
- Very large JSON documents can be slow or memory-heavy in the browser.
- Formatting validates syntax but does not validate business-specific schemas.
FAQ
Does this JSON formatter send data to a server?
No. The formatter uses browser JavaScript to parse and format JSON locally on the page.
Can it validate JSON schemas?
Not yet. This first version validates JSON syntax and formats valid JSON. Schema validation can be added as a later tool.
What is the difference between formatting and validation?
Formatting changes layout and indentation, while validation confirms whether JSON syntax is correct and parseable.
Why does parsing fail on seemingly valid input?
Common causes are trailing commas, single quotes, comments, or unescaped control characters that are not valid JSON.
Can this tool minify JSON safely?
Yes for valid JSON syntax. Minification removes whitespace only and does not change actual keys, values, or structure.