JSON Formatter & Validator

Format, validate, minify, and compare JSON instantly. Tree view, syntax highlighting, real-time error detection.

Client-side Privacy-first No limits
Input
Output

Paste JSON and tap Format JSON above

Ready Lines: 0 Size: 0 B Indent:
Runs entirely in your browser. No data sent to any server.

Paste or upload JSON to format, minify, validate, or explore as a tree. Everything runs client-side — your data never leaves your browser.

What this JSON formatter does

This is a complete JSON toolkit that runs entirely in your browser. Whether you are cleaning up a minified API response, hunting down a stray comma that breaks a config file, or inspecting a deeply nested payload, everything happens locally — nothing is uploaded, logged, or stored on a server.

  • Format & beautify — add clean 2-space, 4-space, or tab indentation so JSON is readable.
  • Minify — strip whitespace to shrink payloads for production and faster transfers.
  • Validate — catch syntax errors in real time with exact line and column hints.
  • Tree view — explore nested objects and arrays, then click any node to copy its path.
  • Convert — export to CSV, YAML, or XML in one click.
  • Comparediff two JSON objects side by side with color-coded changes.

Format vs. minify: what is the difference?

Formatting (also called beautifying or prettifying) adds indentation and line breaks so a human can scan the structure quickly — ideal while you are debugging or reviewing data. Minifying does the opposite: it removes every optional space and newline to make the file as small as possible, which is what you want when shipping JSON over the network or embedding it in code. Either way the underlying data is identical — only the presentation changes. New to this? Read our deep dive on how to minify JSON.

Common use cases

  • Debugging API responses — paste a raw REST or GraphQL response and instantly read it as indented, color-coded JSON. See our guide to debugging APIs with JSON.
  • Fixing broken config filespackage.json, tsconfig.json, and CI manifests fail silently on a trailing comma; the validator points to the exact spot. See common JSON errors.
  • Inspecting nested data — collapse and expand large structures in tree view instead of scrolling through thousands of lines.
  • Preparing data for code — minify before pasting JSON into a script, or copy a single value's path to use in your app.

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Frequently Asked Questions

Is this JSON formatter free to use?

Yes, our JSON formatter is completely free to use with no registration required.

Does this tool validate JSON syntax?

Yes, the tool validates JSON syntax in real-time and displays detailed error messages with line numbers if your JSON is invalid.

Can I use this JSON formatter offline?

Yes, after loading the page once, the tool works entirely in your browser with no data sent to any server.

What is the maximum JSON size supported?

The tool can handle JSON files up to several megabytes, limited only by your browser's memory.

What is the difference between format and minify?

Format (prettify) adds indentation and line breaks to make JSON human-readable. Minify removes all unnecessary whitespace to make the file as small as possible.

Does this tool support JSON5?

Currently, we support standard JSON format. JSON5 features like comments and trailing commas are not supported.