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VALIDATE JSON

JSON Formatter & Validator

Inspect JSON responses and configuration snippets without uploading them. Find syntax errors, format data for readability, or produce compact JSON for use in an application.

File processing runs in a separate editor frame. The advertising scripts on this page cannot read or modify the editor contents.

How to use this tool

  1. Paste a JSON object, array, string, or other valid JSON value.
  2. Leave Pretty print selected to make nested structures easier to inspect.
  3. Enable Compact output for a whitespace-reduced result.
  4. Process, review the validation status, and copy or download the result.
Privacy note: Your input is processed in your browser, not uploaded to our servers. The original file is never overwritten.

Examples

Example input

{"name":"Alex","tags":["csv","tools"]}

Expected result

{ "name": "Alex", "tags": [ "csv", "tools" ] }

What the tool changes (and what it does not)

JSON requires strict syntax: double-quoted keys, commas between object properties, and no trailing commas. JavaScript object literals can be more permissive than JSON, so content copied from source code may fail validation. The formatter uses a real JSON parser to identify syntax errors rather than applying unreliable regular-expression replacements.

Pretty-printing adds indentation and line breaks, making deeply nested objects easier to debug and share. Minifying removes unnecessary formatting whitespace without changing the parsed data structure. Neither operation guarantees that property order has meaning: software should not rely on JSON object key ordering for correctness.

Do not paste secrets such as API keys into shared websites unnecessarily. This tool runs in your browser and does not send the content to its own server, but browser extensions and your device's software may still have access to your screen or clipboard.

Frequently asked questions

Does the formatter accept JavaScript comments?

No. Comments are not valid JSON. Remove them or convert from a different format first.

Will it change the data types?

No. Valid JSON values are parsed and serialized. Numbers stay numeric, strings stay strings, and arrays remain arrays.

Is the input sent to a remote server?

No. Formatting happens in your browser. When advertising is enabled in the future, advertising requests will be separate and never include the editor content.