JSON Formatter & Validator — Free Online Tool

JSON Formatter is a fast, browser-based utility to help you format, validate and beautify JSON data without installing anything. Paste or type your JSON in the editor below and use the provided controls to pretty-print, minify, validate, or download the result. All processing happens locally in your browser — we don't send your JSON to remote servers. This tool is useful for developers, QA engineers, students and anyone who works with structured data.

How it helps

  • Format messy JSON to a human‑readable form with indentation.
  • Find JSON syntax errors quickly — errors include line/column hints where possible.
  • Minify JSON for compact storage or network transport.
  • Copy or download cleaned JSON for use in code, APIs or data files.

Quick example

{ "name": "Alice", "age": 30, "skills": ["react","node","json"] }

Paste the example above into the editor and click Format to see a pretty-printed result. Use Validate to confirm there are no syntax errors.

FAQ — Quick help

How do I fix a JSON error?

The validator displays helpful error messages and (where possible) points to the line causing the issue. Common problems are missing commas, extra/missing brackets, or wrong quotes. Try the example above to compare.

Can I use this for large JSON files?

Yes — the tool can handle fairly large payloads, but very large files (above ~10 MB) are blocked to avoid freezing your browser. You will see a warning if the JSON is large.

Is my data sent to a server?

No — formatting and validation run fully in your browser (client-side). We only request data from the network if you explicitly download or share content.

We display non-intrusive adverts on this site to keep the tools free. Ads are only shown on pages that contain useful content and are not shown on empty or placeholder pages. See the Privacy Policyfor details about advertising and cookies.

Input JSON

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Output

No input
JSON Formatter & Validator — Fast, Private, Reliable
Instantly format, minify and validate JSON in your browser. No servers required.
format
Format & Beautify
Pretty-print JSON for readability and debugging — compatible with API responses and configs.
minify
Minify & Compress
Remove whitespace for smaller payloads — great for transmitting JSON over networks.
validate
Validate & Fix Errors
Find syntax errors and get quick feedback — ideal for testing webhooks and API payloads.
How it works
  1. Paste JSON in the editor and press "Format".
  2. Use "Minify" to compact JSON for transport.
  3. Press "Validate" to check for errors.
Privacy & Safety
This tool runs clientside — by default your data stays within your browser. See our Privacy Policy for details.
Examples
{"name":"John","age":30,"active":true}
If you need help, visit our Guides, read the FAQ, or contact us for support.