Free Online JSON Formatter & Validator

Prettify • Minify • Validate • Sort Keys • Extract Paths

Format and validate JSON instantly. This JSON formatter runs entirely in your browser — no uploads.
Prettify, minify, sort keys, extract values by path, and optionally validate against a JSON Schema subset.
Find (in input)
Extract path
Options
Output / Diff / Schema
Output updates when you prettify/minify/sort/extract. Diff compares current input vs last snapshot.
JSON Schema (subset) — optional
Schema tools
Supports subset:
• type, enum, const
• required, properties, items
• min/max (number), minLength/maxLength
• minimum/maximum

About this tool

Format JSON online without sending it anywhere. This page is a browser-based JSON formatter and validator: it can pretty print (prettify) JSON for readability, minify JSON for compact payloads, and validate strict JSON syntax to catch missing commas, quotes, or brackets. It’s built for fast API debugging, log cleanup, and webhook payload inspection.

Common use cases

  • Prettify JSON responses from REST/GraphQL endpoints
  • Minify JSON before sending requests or saving fixtures
  • Validate JSON and pinpoint syntax issues quickly
  • Sort object keys to make diffs stable and reviewable
  • Extract values using JSON paths when you only need one field

How it works

The formatter uses native browser parsing for strict validation and transformations. Your input stays on your device: there’s no account, no upload step, and no backend processing required for formatting/validation. Output updates when you run actions like prettify, minify, sort, or extract, and the diff view helps compare your current input against a previous snapshot.

FAQ

Does this send JSON to a server?

No. Formatting and validation run locally in your browser.

Can it handle large JSON?

Yes. Up to your browser’s memory limits. If a payload is huge, try minify/pretty print in steps.

Why “validate” fails when it looks like JSON?

JSON is stricter than JavaScript objects (double quotes, no trailing commas, no comments). One invalid character will fail strict parsing.