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. Up to 100 KB per share.

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, or share — Use the search bar to find values, collapse sections to focus on what matters, download the formatted result, or create a share link that stays live for 7 days.

Where your JSON goes

Almost everything JSON Hero does happens locally. Formatting, minifying, validating, searching, folding, unescaping 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. 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. Everyone who can see that message sees that snippet.
How long it lasts — 7 days from upload. 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.
No accounts — sharing needs no sign-up, so a share is not tied to an identity, and 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