Free JSON Tools Online

Format, validate, minify, compare, and convert JSON instantly in your browser. No signup required. Your data never leaves your device.

JSON Validator

Validate your JSON with clear, helpful error messages that show exactly where the problem is including line and column number.

Open Validator
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JSON Minifier

Compress your JSON by removing all whitespace and formatting. See exactly how much space you saved with before/after size comparison.

Open Minifier

JSON Diff Tool

Compare two JSON objects side by side. See additions, deletions, and changes highlighted clearly with a structured diff view.

Open Diff Tool

Instant Processing

All tools process JSON in real-time as you type with zero server round-trips.

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100% Private

Your data never leaves your browser. Everything runs client-side with JavaScript.

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Mobile Friendly

Works on any device. Responsive design optimized for desktop and mobile browsers.

Why Use JSONKit?

JSONKit provides a complete suite of free JSON tools that run entirely in your browser. Whether you need to format messy JSON from an API response, validate a configuration file, minify JSON for production, convert data to CSV for a spreadsheet, or compare two JSON documents to find differences, JSONKit has you covered.

Built for Developers

Every tool features syntax highlighting with a code-editor color scheme, monospace fonts, line numbers, and keyboard-friendly interfaces. Drag and drop JSON files directly into any tool, or paste from your clipboard.

No Sign-Up, No Limits

All tools are completely free with no usage limits, no account required, and no ads tracking your data. JSONKit is a simple, fast utility site for developers who work with JSON daily.

Common JSON Use Cases