Developer tool · local processing

JSON Formatter & Validator

Paste raw JSON to format, validate, minify and inspect it in a collapsible tree view. The main parsing and formatting workflow runs in your browser.

Readable formatting Beautify minified API responses with clear indentation and syntax highlighting.
Validation feedback See JSON parse errors while keeping your original input available for editing.
Tree inspection Expand and collapse nested arrays and objects to inspect large payloads more easily.

Input raw JSON

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Formatted tree viewer

Awaiting valid JSON… Paste code on the left to start formatting and validation.
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What this JSON formatter includes

This JSON formatter helps you turn minified or hard-to-read JSON into a readable structure. It is useful for API responses, configuration files, webhook payloads, debugging logs and code examples.

You can beautify JSON, minify it, validate syntax, inspect nested data in a tree viewer, copy the formatted result and export the tree view as a PNG image for documentation or tickets.

For Chinese users, this page is also useful as a JSON格式化工具, JSON校验工具, JSON压缩工具 and JSON树形查看器.

Local processing note

Formatting, parsing and validation are handled in your browser. For normal use, the JSON you paste into the editor is not uploaded to Mini-Tools.uk.

Common use cases

  • Beautify a minified API response before reading or sharing it.
  • Validate a JSON payload and locate parse errors while debugging.
  • Inspect deeply nested objects and arrays in a collapsible tree view.
  • Minify formatted JSON before storing it in an environment variable or config file.

Is this JSON formatter private?

Yes. Formatting and validation run in your browser. Your JSON is not uploaded to Mini-Tools.uk.

Can it validate broken JSON?

Yes. If parsing fails, the page shows the error message while keeping the original input available for editing.

Can it handle large nested JSON objects?

The tree viewer is designed for nested JSON. Very large files still depend on your browser memory and device performance.