What is a JSON Formatter?
JSON Formatter is an online tool that helps you format (beautify), minify, and validate JSON data — completely free, running in the browser without installing any software.
JSON (JavaScript Object Notation) is the most popular data format in web and API development. When working with raw JSON from an API response or config file, you often need to format it to make it readable or minify it to reduce its size.
Key Features
- Beautify — Automatically indents, adds line breaks, and displays clearly structured JSON. Supports 2 or 4 spaces.
- Minify — Removes spaces and line breaks → 1-line JSON, saving bandwidth.
- Validate — Detects JSON syntax errors with clear error messages (line, position).
- Syntax Highlighting — Color-coded differentiation of keys, values, strings, numbers, and booleans.
- Copy & Paste — Paste JSON in, format it, and copy with 1 click.
- Client-side — Data does not leave your browser. Safe for sensitive data.
How to use
- Visit Metoolzy JSON Formatter
- Paste raw JSON into the Input box (left side)
- Click Beautify to format it nicely, or Minify to shrink it
- The result appears in the Output box (right side) — click Copy to duplicate
When do you need to format JSON?
- Debugging API responses — data returned from a REST API is often a 1-line JSON
- Reading config files (package.json, tsconfig.json, docker-compose)
- Checking webhook payloads
- Preparing test data for Postman / Insomnia
- Minifying JSON before saving it to a database or sending it over the network
Frequently Asked Questions
Does the JSON Formatter save my data?
No. All processing happens in the browser (client-side). JSON data is not sent to the server.
Is there a limit to the JSON size?
There is no hard limit, but very large JSON files (>10MB) may slow down your browser.
Does it support JSON5 or JSONC (with comments)?
Currently, it only supports standard JSON. JSON5 and JSONC (JSON with comments) will be supported in the future.
👉 Try JSON Formatter for free →
See more: XML Formatter · SQL Formatter · CSV ↔ JSON Converter
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