JSON Formatter and Validator
Format, minify and validate JSON in your browser. Keep number spellings, key order and duplicate members intact while changing only whitespace.
Free · No signup · No watermark · On-device processing
Paste JSON
How to format or minify JSON
- Paste a complete JSON document into the input.
- Choose Format for two-space indentation or Minify to remove unnecessary whitespace.
- If syntax is invalid, read the browser’s parse error and correct the input.
- Copy the result or download a .json file.
Formatting without changing JSON values
This tool validates standard JSON syntax, then works with the original tokens rather than serializing parsed JavaScript values. That matters for large integer literals, decimal spellings and duplicate object member names. Formatting should not silently round a number or drop a repeated key.
Format adds line breaks and two-space indentation. Minify removes whitespace outside strings. Escapes, string contents, member order and number text are retained. The formatter does not sort keys, repair malformed input, run JavaScript, resolve references or transform data into a schema.
JSON requires double-quoted member names and strings. Comments, trailing commas, undefined and JavaScript function expressions are not accepted. Duplicate member names can be syntactically accepted but interpreted differently by downstream software; retaining them is not an endorsement of that design. The parse error wording is supplied by the browser and can differ across browsers.
Working with tabular records? Try CSV ↔ JSON Converter.
Privacy and browser support
Your input is handled in this browser tab. Selected files and entered text are not sent to Varento Tools by this tool. Some specialized libraries load only when needed. A browser with JavaScript and sufficient device memory is required. Read our local-processing explanation.
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Frequently asked questions
Is this tool free without daily usage limits?
Yes. Varento Tools has no signup, accounts, usage-count caps, paywalls or watermarks. Device memory, format support and browser restrictions can still limit technically demanding files.
Does formatting round large integers?
No. The output uses the original number tokens, so formatting does not serialize them through JavaScript’s limited-precision Number type.
Are duplicate keys removed?
No. They remain in the output. Downstream parsers may keep only the last value, so remove unintended duplicates yourself.
Can it fix invalid JSON?
It reports syntax errors but does not guess corrections. Comments, single-quoted strings and trailing commas need to be corrected.
Is pasted JSON uploaded?
No. Formatting and validation run in this tab. Do not paste secrets into a shared or untrusted browser.