About JSONViewer

JSONViewer is a free, fast, and privacy-focused online tool that helps developers, data analysts, and anyone working with JSON data to instantly visualize, format, and explore their data.

Our Mission

We believe developer tools should be simple, fast, and free. JSONViewer was built to give everyone a reliable JSON viewer that works entirely in the browser — no sign-up, no data uploads, no cost.

Features

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Interactive Tree View

Explore JSON as a fully collapsible tree. Expand or collapse any node with a single click.

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Live Auto-Render

The viewer updates instantly as you type or paste — no button clicks needed.

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Search & Highlight

Instantly find any key or value across your entire JSON document.

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100% Private

All processing happens in your browser. Your data never leaves your device.

✓

JSON Validation

Invalid JSON is caught immediately with a clear, helpful error message.

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Smart Arrays

Primitive arrays shown inline. Complex arrays shown as indexed collapsible nodes.

Technology

JSONViewer is built with plain HTML, CSS, and JavaScript — no frameworks, no dependencies, no tracking scripts. It works in all modern browsers and even offline once loaded.

Privacy

We take your privacy seriously. JSON data you paste into the tool is processed entirely client-side. We do not store, log, or transmit any of your JSON content. Read our full Privacy Policy.