JSON Formatter
Format, validate, and minify JSON with syntax highlighting and error detection. Free, runs in your browser, no signup required.
Format, Validate, and Analyze JSON
The JSON Formatter formats, validates, and analyzes JSON data directly in your browser. Whether it's an unformatted API response, a minified config file, or broken JSON — this tool makes it readable, finds syntax errors, and displays the data structure clearly.
Pretty-Print and Minify
Paste unformatted JSON and get a cleanly indented, syntax-highlighted output instantly. Conversely, you can minify formatted JSON — ideal for reducing file size or making JSON compact for API requests.
JSON Validation
The formatter checks your JSON for syntactic correctness and displays errors with line numbers and descriptions. Common mistakes like missing quotes, trailing commas, or mismatched brackets are detected immediately.
Syntax Highlighting and Tree View
Strings, numbers, booleans, null values, and keys are color-coded. The interactive tree view lets you expand and collapse nested objects and arrays — especially useful for deeply nested API responses.
Typical Use Cases
- Debug and analyze REST API responses
- Inspect GraphQL responses
- Check config files (package.json, tsconfig.json)
- Examine webhook payloads
- Format JSON data for documentation
- Repair broken JSON exports from databases
Privacy
Your JSON data stays entirely in your browser. No upload, no server, no tracking. Sensitive API keys, tokens, or personal data in your JSON never leave your machine.