Format, beautify, inspect, and validate JSON data with syntax error detection, collapsible tree view, and custom indentation.
The JSON Formatter & Validator helps you clean, organize, and debug JSON data quickly. If you have minified single-line API responses or unformatted configuration files, this tool turns them into neat, readable code.
All parsing and validation run strictly within your browser memory. If your JSON has a typo—such as a missing quote, a trailing comma, or an unclosed bracket—the validator highlights the exact line so you can fix it immediately.
Developers paste API outputs or webhook responses to inspect deeply nested keys and verify data types.
Engineers format configuration files and project manifests before saving them to source control.
Data analysts format JSON document exports from databases to check data accuracy and field names.
Enter or paste your raw or minified JSON text into the input panel.
Choose your preferred spacing: 2 spaces, 4 spaces, or tab indentation.
Click "Format" to beautify your JSON, or toggle "Tree View" to expand and collapse nested sections.
Instant syntax validation with clear line and character error indicators
Customizable indentation spacing (2 spaces, 4 spaces, or tabs)
Dual viewing modes: Syntax-highlighted text editor and interactive tree view
One-click clipboard copy, minification toggle, and JSON file download
100% private in-browser execution with zero server logging
Turn a single-line user object into indented JSON.
{"id":10,"name":"Sarah","roles":["editor","admin"],"active":true}Indentation makes nested arrays and object keys readable at a glance.
Solution: Standard JSON forbids trailing commas after the last item in an array or object. Delete commas immediately before closing } or ] brackets.
Solution: JSON strictly requires double quotes ("...") around all string values and property keys. Replace single quotes with standard double quotes.
MWT Labs tools are built using modern web primitives—including WebAssembly, Web Workers, and native HTML5 Canvas / Cryptography APIs. When you process images, parse PDF documents, format JSON payloads, or calculate financial schedules, execution happens strictly within your local browser memory sandbox.
This tool parses your JSON string using standard JavaScript object rules and adds clean indentation, line breaks, and colored syntax. It highlights syntax errors immediately if a quote, comma, or bracket is misplaced.
No. All parsing, validation, and tree rendering happen entirely in your browser's local memory. Sensitive API responses, auth tokens, and internal configurations never leave your computer.
Code View lets you directly edit and format your raw text with customizable indentation (2 spaces, 4 spaces, or tabs). Tree View provides a visual hierarchy where you can expand or collapse nested objects and arrays.
Standard JSON requires double quotes around all keys and string values, and does not permit trailing commas after the final item in an object or array. Removing trailing commas usually resolves the issue.
Yes. It easily handles JSON structures with thousands of lines. For very large files exceeding several tens of megabytes, code view is recommended over tree view for maximum rendering speed.