DevLocal only
JSON Formatter + Validator
Pretty print, minify, sort keys, and validate JSON safely.
jsonformatvalidatorprettifyminify
⌘⇧CCopy output
Your data stays in your browser — nothing is uploaded.
Input
Size: 0 B
Options
Output mode
Formatting
Output
Paste JSON to format and validate.
Output
Output is plain text only (safe by design).
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What is JSON Formatter + Validator?
JSON Formatter + Validator is a free online tool that formats, validates, and minifies JSON data instantly. Paste messy JSON and get perfectly indented, color-highlighted output with error line pointers. No data ever leaves your browser.
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How it Helps
- ✓Instantly format and validate API responses, config files, or any JSON data.
- ✓Detect syntax errors with precise line and column indicators.
- ✓Minify JSON for production use or sort keys for consistent diffs.
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Usage Guide
- 1Paste your raw JSON into the input area.
- 2Choose Format, Minify, or Sort Keys from the action buttons.
- 3Copy the formatted output or download it as a .json file.
Frequently Asked Questions
No. All formatting and validation happens locally in your browser using JavaScript. Your data never leaves your device.
Yes, the tool handles large JSON efficiently. For extremely large files (50MB+), performance depends on your browser and device.
It detects missing commas, unclosed brackets, trailing commas, invalid escape sequences, duplicate keys, and all standard JSON syntax errors.
Yes! Use the Sort Keys feature to recursively sort all object keys, making JSON output consistent and easier to diff.