How do I format or pretty-print JSON online?

Click Load JSON, paste your document and press Enter (or Confirm). It parses and renders as a collapsible tree instantly, showing the exact line and column of any error.

Can I edit the JSON in the tree?

Yes. Hover any node to reveal its menu and add a child, delete it, or edit its value — if you type valid JSON into an edit box it expands into that node's children automatically.

Can I search inside the tree?

Yes. The Find bar supports both plain text and path expressions like $.config.theme[0].name, jumping straight to the matching node.

Does this JSON tool upload my data?

No. Parsing, tree rendering, editing and diffing all run locally in your browser; your JSON never leaves your device.

JSON Formatter, Tree Editor & Diff

A professional in-browser JSON editor: load a document, browse it as a collapsible tree, edit nodes inline, search by path, get statistics and diff against the original — all locally, no upload. Stays smooth on files up to ~20 MB.

Compare two documents. Both sides are parsed, formatted and their object keys sorted alphabetically before comparing, so only real structural or value differences show.

JSON A (base) JSON B (compare)

A real JSON editor, not just a formatter

Load any document with the Load JSON button and it renders as a collapsible tree you can actually work in. Hover a node to reveal its menu: add a child, delete it, or edit its value — type valid JSON into an edit box and it expands straight into that node's children.

Find anything by path

The Find bar understands both plain text and path expressions. Type $.config.theme[0].name to jump directly to a deep node, or search any key or value across the whole document with match counts and Prev/Next.

Statistics & change tracking

Statistics reports total keys, how many keys sit at each level, the deepest path in the document, node count and character size.
View Changes jumps to the Diff tab and compares your current tree against the original you loaded — added, removed and changed nodes are color-coded with a running total.

Frequently asked questions

Is my data sent anywhere? No. Parsing, rendering, editing and diffing all happen in your browser; the page works offline.
How big a file can I use? Comfortably into the tens of megabytes — heavy work is offloaded to a background thread and only the visible part of the tree is drawn, so it won't freeze. For very large files use "Choose file…" in the Load dialog.
Does it support comments or trailing commas? Strictly no — that's not valid JSON by spec, and pointing out where strict parsers choke is exactly what a validator should do.