JSON Formatter & Validator

Paste JSON below to format, validate, or minify. Free, no signup.

Use via API

All these tools are also available as a REST API:

curl -H "X-API-Key: YOUR_KEY" -X POST \
-d '{"input":"{\"a\":1}"}' \
https://api.fengdeagents.site/api/json/format

About This Tool

This free JSON formatter lets you quickly prettify, validate, and minify JSON data directly in your browser. It runs entirely client-side — your data never leaves your browser.

Need programmatic access? Our DevTools API offers JSON formatting, validation, diffing, flattening, and querying via a simple REST API with a free tier (100 requests/day).

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