JSON Formatter & Validator
Processed locallyFormat, validate and minify JSON online — processed entirely in your browser. Supports 2-space, 4-space and tab indentation.
About JSON Formatter & Validator
The JSON Formatter & Validator is a browser-based tool that helps developers format, validate, and minify JSON data. All processing happens entirely in your browser—no data is ever sent to our servers, so you can safely work with sensitive API responses and configuration files. Common use cases include debugging API responses, preparing configuration files for deployment, validating JSON before committing to version control, and exploring nested data structures. The tool supports multiple indentation styles: 2-space, 4-space, and tab. A tree view lets you expand and collapse nested objects and arrays for easier navigation. Invalid JSON is highlighted with precise line and column numbers, making it easy to fix syntax errors. The minifier removes all unnecessary whitespace to reduce file size for production. Whether you're working with a few lines or large API payloads, this tool keeps your workflow fast and private. It integrates with the nuqs URL state system—your formatted JSON can be shared via link. Pair it with our JSON to TypeScript generator for type definitions, or the OpenAPI validator for API specs. No sign-up required; everything runs client-side.