The Fastest JSON Formatter
Format, validate, diff & convert JSON instantly. 100% private — your data never leaves your browser.
Professional JSON Toolkit for Developers
JSON-parser.net is a comprehensive, privacy-first JSON toolkit built for modern developers. All processing runs locally using Web Workers — your sensitive data never leaves your device. Whether you're debugging API responses, validating configuration files, or comparing JSON structures, our tools help you work faster and more efficiently.
How to Use the JSON Formatter
Input Your JSON
Paste JSON directly, drag-and-drop a .json file, or use the sample data button to get started.
Choose Your Action
Click Format to prettify, Minify to compress, or Validate to check for errors.
Explore Output Tabs
Use Tree for visual navigation, Diff to compare files, or Schema to validate against a schema.
Export Results
Copy to clipboard with one click, or download as a .json file. Share with teammates instantly.
⌨️ Keyboard Shortcuts
On Windows/Linux, use Ctrl instead of ⌘
Complete Feature Guide
JSON Formatter
Transform minified JSON into beautifully indented, readable code. Choose 2 or 4 space indentation. Preserves original data types and structure while making nested objects easy to navigate.
JSON Validator
Instantly detect syntax errors with precise line and column numbers. Identifies common issues like trailing commas, unquoted keys, single quotes, and invalid escape sequences with helpful fix suggestions.
Tree View
Visualize your JSON as an interactive, collapsible tree structure. Expand/collapse nodes, search for specific keys or values, and click any node to copy its JSONPath. Perfect for exploring large, deeply nested data.
JSON Diff
Compare two JSON documents side-by-side with highlighted differences. See additions in green, deletions in red, and modifications clearly marked. Essential for reviewing API response changes or config file updates.
JSON ↔ YAML
Convert between JSON and YAML formats instantly. Toggle input mode to work natively with YAML files. Perfect for Kubernetes configs, CI/CD pipelines, and any DevOps workflow requiring format conversion.
Schema Validation
Validate JSON against JSON Schema (Draft 2020-12). Powered by AJV, supports $ref, conditional schemas, format validation, and custom keywords. Essential for API contract testing and data quality.
🆕 TypeScript & Zod Schema Generator
New in 2025: Generate TypeScript interfaces and Zod validation schemas directly from your JSON data. Perfect for AI application development — validate LLM responses, ensure type safety, and catch hallucinations before they crash your app.
100% Private & Secure
- No server uploads — All processing happens in your browser using Web Workers
- Works offline — Install as PWA for full functionality without internet
- No tracking — We don't collect, store, or analyze your JSON data
- Enterprise safe — Perfect for sensitive API keys, credentials, and proprietary data
Technical Specifications
- JSON Schema: Draft 2020-12, 2019-09, draft-07, draft-04
- Validator: AJV (fastest JSON Schema validator)
- Max file size: No hard limit (multi-MB files supported)
- Editor: CodeMirror 6 with syntax highlighting
- Framework: Astro + Solid.js (island architecture)
- PWA: Installable, works offline
Who Uses This Tool?
🔌 API Developers
Debug API responses, validate request/response payloads, format webhook data
🤖 AI/ML Engineers
Generate validation schemas for LLM outputs, structure training data, parse embeddings
⚙️ DevOps Engineers
Convert JSON ↔ YAML for Kubernetes, validate CI/CD configs, compare deployment files
📊 Data Analysts
Explore nested data structures, extract values with JSONPath, validate data quality
🎨 Frontend Developers
Generate TypeScript types from API responses, mock data for testing, debug state
📱 Mobile Developers
Inspect network traffic, validate deep link configs, debug push notification payloads
Frequently Asked Questions
What is JSON and why do I need a formatter?
JSON (JavaScript Object Notation) is a lightweight data format used by virtually every modern web API, database, and configuration system. A JSON formatter transforms compressed, hard-to-read JSON into properly indented, human-readable code. This is essential for debugging API responses, understanding data structures, and catching syntax errors. Our formatter also validates JSON syntax, ensuring your data is correctly structured before use.
Is my data safe? Do you store or transmit my JSON?
Your data never leaves your browser. All JSON processing happens 100% client-side using Web Workers. We don't have servers that receive, store, or process your data. This makes our tool safe for sensitive information like API keys, credentials, personal data, and proprietary business data. You can even disconnect from the internet and continue using the tool offline.
What's the maximum file size I can process?
There's no hard limit. We use Web Workers to process JSON in a separate thread, preventing UI freezes even with multi-megabyte files. In practice, files up to 50MB work smoothly on modern devices. For extremely large files (100MB+), performance depends on your device's memory and CPU. The tree view may slow down with millions of nodes, but formatting and validation remain fast.
What JSON Schema versions do you support?
We support all major JSON Schema drafts: Draft 2020-12 (latest), Draft 2019-09, Draft-07, and Draft-04. Our validator is powered by AJV, the fastest and most feature-complete JSON Schema validator available. It supports advanced features like $ref references, conditional schemas (if/then/else), format validation, and custom keywords.
Can I use this offline?
Yes! JSON-parser.net is a Progressive Web App (PWA). You can install it on your device (look for the install button in your browser's address bar) and use it without an internet connection. All features work offline, including formatting, validation, diff, schema validation, and YAML conversion. Perfect for developers who need reliable tools while traveling or in low-connectivity environments.
How do I compare two JSON files (diff)?
Click the Diff tab in the output panel. You'll see two input areas: paste your first JSON in the left editor and second JSON in the right editor. Click "Compare" to see a side-by-side diff with color-coded changes: green for additions, red for deletions, and yellow for modifications. You can also see a semantic diff that understands JSON structure, not just text differences.
What is JSONPath and how do I use it?
JSONPath is a query language for extracting values from JSON, similar to XPath for XML. Use the Path tab to search your JSON data.
Examples: $.store.book[0].title gets the first book's title, $..author finds all author fields at any depth,
$.store.book[?(@.price < 10)] filters books under $10. It's incredibly powerful for extracting specific data from complex nested structures.
How do I generate TypeScript types from JSON?
Use the TS/Zod tab! Paste your sample JSON, and we'll automatically generate TypeScript interfaces and/or Zod validation schemas. Options include: root type name, interface vs. type keyword, optional fields, and strict null checks. This is especially useful for AI developers who need to validate LLM responses — generate a Zod schema from a sample output, then use it to catch malformed AI responses.
Learn More
Explore our comprehensive guides and tutorials to master JSON and related technologies:
Help shape this tool
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