JSON Formatter, Viewer & Editor Features

Everything you need to work with JSON, right in your browser. No sign-up, no installation. Formatting, validating and searching never leave your device — your JSON is only uploaded if you choose to create a share link.

JSON Formatter & Beautifier

Pretty-print JSON with proper indentation and color-coded syntax highlighting. Supports both strict and tolerant parsing for malformed JSON, so you can format even broken payloads. Handles large files with a loading indicator so the UI stays responsive.

JSON Minifier

Compact JSON to a single line by removing all whitespace. Use the keyboard shortcut Cmd/Ctrl+Shift+M for instant minification. Perfect for reducing payload size before sending JSON over the network or storing it efficiently.

JSON Validator

Validate JSON automatically when formatting. Invalid JSON is flagged with clear error messages. Best-effort formatting shows you where problems are, even in broken input. Uses JSON.parse for strict validation and a tolerant parser as a fallback.

JSON Viewer with Collapsible Tree

View JSON in a structured format with fold/unfold controls for every object and array. Collapse all or expand all with one click. Bracket pair highlighting helps navigate deeply nested structures. Line numbers keep you oriented in large documents.

Search & Find in JSON

Real-time search with highlighted matches across your entire JSON document. Navigate between matches with Next/Previous buttons or keyboard shortcuts. Instantly find keys, values, or patterns. Match count shows you exactly how many results were found.

Load JSON from URL or File

Import JSON from any public URL or upload a local .json file. Drag and drop support included. JSON Hero also auto-detects JSON in your clipboard and offers to paste it for you. Fetch API responses directly by entering the endpoint URL.

Clipboard Auto-Detection

JSON Hero detects JSON content in your clipboard when you open the page. Escaped JSON strings are automatically unescaped and formatted. Paste from any source — API responses, log files, or code editors — and get clean, readable JSON instantly.

Download Formatted JSON

Export your formatted or minified JSON as a downloadable text file with one click. Save clean, well-formatted output directly to your device for use in other tools, documentation, or version control.

Share JSON with a Link

Turn the JSON in your editor into a short link like jsonhero.dev/s/AbC123XyZ0 and send it to anyone — no account required. Add an optional name, and paste the link into Slack or a pull request to get a preview card showing the shape of the data. This is the one feature that uploads your JSON: shared documents are stored on our servers and deleted automatically after 7 days on the free plan, or later with Pro. Up to 100 KB per share on the free plan, or 1 MB with Pro.

Compare Two JSON Documents

See exactly what changed between two JSON documents on the JSON diff page, or click Compare in the editor to take your document with you. Added, removed and changed values, and values that changed type, are shown side by side or as a unified diff, with object key order ignored. Match array items by a key such as id so a reordered list doesn't read as one big change, ignore noisy fields like updatedAt, search both documents at once, and open a compatibility report that flags the changes most likely to break code reading the data. The comparison runs in your browser; Share sends both documents, with your rules, as one link. Up to 100 KB per side on the free plan, or 1 MB with Pro.

Free and Pro

Every feature on this page is free, with no sign-up and no ads. The free plan works with documents up to 100 KB — in the editor, from a file, from a URL, per share link and on each side of a comparison — and share links last 7 days, with up to 30 new links an hour and 100 a day.

Pro is an optional subscription for people who work with bigger JSON or share it more: documents up to 1 MB everywhere, share links that last longer, up to 500 new links a day, priority replies by email, and for comparisons: no limit on ignore and match rules, rule presets saved in your browser, and exports as a JSON Patch, a unified diff or Markdown. It costs ₹99 a month or ₹999 a year in India, and $4.99 a month or $49 a year elsewhere. See Pricing for the full comparison.

How to Format JSON Online

Open JSON Hero — Visit jsonhero.dev in any modern browser. No download or installation needed.
Paste your JSON — Paste JSON into the editor, or click "Load JSON" to import from a URL or file.
Click Format — Your JSON is instantly pretty-printed with syntax highlighting, line numbers, and fold controls.
Search, edit, download, compare, or share — Use the search bar to find values, collapse sections to focus on what matters, download the formatted result, click Compare to see what changed against another JSON document, or create a share link that stays live for 7 days on the free plan.

Where your JSON goes

Almost everything JSON Hero does happens locally. Formatting, minifying, validating, searching, folding, unescaping, comparing and downloading are all handled by JavaScript on your device, and that JSON is never uploaded.

Sharing is the exception. When you click Share, the contents of the editor are uploaded so that the link has something to serve; sharing a comparison uploads both documents, with their names and your comparison rules. Here is exactly what that means:

What we store — the JSON text itself, in a private storage bucket, plus metadata: its size, a checksum, a short preview snippet, an auto-generated summary such as JSON object · 3 keys, any name you add, a view count, and a salted hash of your IP address used only for rate limiting.
Who can read it — anyone with the link. Share links are not password protected; their only protection is a random 10-character id that is effectively unguessable. Links are never listed in our sitemap, but we do not block crawlers from them either, so a link posted somewhere public can be indexed.
Link previews — when a share link is unfurled in Slack, X or a chat app, the preview card shows the beginning of your JSON, or for a comparison, the first few changes with their values. Everyone who can see that message sees that snippet.
How long it lasts — 7 days from upload on the free plan, longer with Pro. When that time is up, a daily cleanup job then deletes the stored JSON and its preview image, the link begins reporting “Share expired”, and the id is retired so it is never reused.
Not tied to your account — sharing needs no sign-up, and even when you are signed in a share is stored without your name or account; only your plan is recorded, to apply its limits. We do not use stored JSON for anything beyond serving the link.

Because a share link can be read by anyone who gets hold of it, do not share credentials, access tokens, or personal data through one. If you need a share taken down before it expires, email hello@jsonhero.dev.

Ready to format your JSON?

No sign-up, no installation. Just paste and format.

Open JSON Hero Editor