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JSON Formatter

Validate, format, and minify JSON data instantly in your browser.

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How to Format JSON Online for Free

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About This Tool

Free JSON formatter and validator online — paste raw, minified, or malformed JSON and instantly get it formatted with proper indentation, syntax highlighting, and error messages pinpointing exactly where the JSON is invalid. Also minifies JSON back to a compact single line for production use. 100% browser-based: your JSON never leaves your device. Developers use this tool daily to debug API responses, inspect configuration files, validate JSON schemas before committing, and make minified JSON readable for code review. The formatter supports nested objects and arrays of any depth and handles very large JSON documents. Paste your JSON, fix errors using the highlighted line numbers, then copy the formatted output.

How to Use

  1. 1

    Paste your JSON

    Paste raw, minified, or malformed JSON into the input field.

  2. 2

    Format or Minify

    Click Format to beautify with indentation, or Minify to compress to a single line.

  3. 3

    Fix errors

    If your JSON has errors, the tool highlights the problem and shows an error message. Fix the issue and reformat.

  4. 4

    Copy the output

    Copy the formatted or minified JSON to your clipboard.

Frequently Asked Questions

What is JSON formatting?+
JSON formatting (or "pretty printing") adds consistent indentation and line breaks to JSON so it is human-readable. Minification removes all whitespace to reduce file size for production use.
Why does my JSON fail validation?+
Common JSON errors include trailing commas after the last item in an array or object, single quotes instead of double quotes around strings, unquoted property keys, and control characters in string values.
Is there a size limit?+
There is no imposed limit. However, very large JSON files (over 10 MB) may be slow to process in the browser depending on your device.

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