JSON Editor · Visualizer

JSON Editor · Visualizer

Free · In-browser

Format, validate, and explore JSON with a live tree view—no upload required.

Load from URL

Enter an HTTP or HTTPS URL. The response body will replace the editor content.

Cross-origin URLs need CORS enabled on the server.

Clear editor?

This removes all text from the editor. This cannot be undone.

Input JSON

Paste or type code

Tree View

Tree preview

Valid JSON will appear here as an expandable tree after you paste or format your document.

Free online JSON editor with a live tree view

This page is a browser-based workspace for working with JSON: you edit text on the left, and when the document parses successfully, an interactive tree appears on the right. There is no sign-in, no upload step, and no backend that stores your payload.

Why pair an editor with a tree?

Minified API responses and log lines are hard to scan as a single block of text. A tree viewer turns objects and arrays into nodes you can expand or collapse, so you can jump to the field you care about without counting braces. Keeping the editor and tree on one screen means you can fix a value in text and immediately see the structure update.

What this tool does

  • Format — pretty-print valid JSON with consistent indentation.
  • Compress — minify JSON by removing unnecessary whitespace.
  • Example — load a small sample document to explore the UI.
  • Copy — send the current editor text to the clipboard.
  • Load from URL — fetch JSON over HTTP(S) when the target allows it (CORS permitting).
  • Tree view — color-coded types, expand/collapse, and expand-all / collapse-all controls.

Privacy and client-side processing

Formatting and validation execute locally in your browser. We do not operate a paste-ingestion API for this MVP. If you load JSON from a URL, your browser contacts that URL directly—you should only fetch endpoints you trust.

Quick JSON syntax reminders

JSON is strict: keys and strings use double quotes, booleans are true or false, and null is its own value. Trailing commas after the last property or array item are not allowed. Comments are not part of the JSON standard—strip them before parsing if your source file includes them.

Frequently asked questions

Is my JSON sent to your servers?
No. Parsing, formatting, and tree rendering run in your browser. Data stays on your device unless you use Load from URL, which fetches directly from the URL you enter.
What does the Valid JSON badge mean?
It reflects whether the current editor text parses as standard JSON. It is syntax validation only—not JSON Schema or business-rule checking.
Why does Load from URL fail sometimes?
Browsers enforce CORS. If the remote server does not allow your origin, the fetch fails. Copy the response into the editor instead, or use a URL that permits cross-origin access.
Is there a file size limit?
There is no hard server cap because nothing is uploaded. Very large documents (roughly over 2 MB) may show a performance warning and can slow the tab depending on your device.
Can I use single quotes or trailing commas?
Standard JSON requires double-quoted keys and strings, and does not allow trailing commas. The editor highlights parse errors so you can fix them before formatting.
Does the tree update while I type?
Yes. After you pause typing, the tree refreshes on a short debounce (about 300 ms) when the document is valid JSON.