The Fastest JSON Formatter
Format, validate, diff & convert JSON instantly. 100% private — your data never leaves your browser.
Schema Validation
JSON ↔ YAML
Smart Diff
Tree View
Professional JSON Toolkit
All processing runs locally using Web Workers — your data never leaves your device.
Quick Start
- Paste JSON or drag-drop a file
- Use toolbar for Format, Minify, Validate
- Switch tabs: Tree, Diff, Schema
- Copy or download results
Shortcuts
Format⌘⇧F
Minify⌘⇧M
Validate⌘⇧V
Palette⌘K
100% Private
- No server uploads
- Works offline (PWA)
- Open source
Features
Tree View
JSONPath
Schema Gen
Smart Diff
YAML Convert
Live Validate
Use Cases
API Development Config Management Data Analysis DevOps & CI/CD Debugging API Documentation
Learn More: FAQ & Technical Details
JSON Schema Validation (Draft 2020-12)
Powered by AJV, the fastest JSON Schema validator. Supports conditional schemas, format validation, $ref, and custom keywords.
Is my data secure?
All processing happens in your browser. Data never leaves your device.
Max file size?
No hard limit. Web Workers handle multi-MB files smoothly.
Works offline?
Yes! It's a PWA. Install it for offline access.
Schema version?
Draft-2020-12 (latest). Also supports draft-07 and draft-04.
Help shape this tool
We're building this for you. Tell us what you want, what you like, and what you don't — and we'll keep making it better.