A free online JSON viewer, formatter, validator, editor and diff tool that runs in your browser.
Format, minify, validate, search and compare JSON with no sign-up and no ads.
Your JSON stays on your device unless you click Share.
Features · Pricing · FAQ · Privacy · Changelog
- Format and beautify. Pretty-print with indentation and syntax highlighting, plus line numbers and bracket matching. Pasted JSON is formatted straight away, and a tolerant parser still gives you best-effort formatting when the JSON is malformed.
- Validate. Input is checked with
JSON.parsewhen you format, and invalid JSON is flagged with a warning. - Minify. Compact JSON to a single line.
- Collapsible tree. Fold any object or array, or collapse and expand everything in one click.
- Search. Real-time search with every match highlighted across the document.
- Load JSON your way. Paste it, drag and drop a
.jsonfile, or fetch it from a public URL that allows cross-origin requests (CORS). - Clipboard detection. If the editor is empty when you open or return to the page, valid JSON on your clipboard is pasted in for you. Your browser may ask for permission first.
- Extract JSON from logs. Paste a log line or other text with JSON inside it, like
request: {…} response: {…}, and the JSON is pulled out and formatted. - Unescape. Escaped JSON strings like
{\"id\":1}are detected and turned back into readable JSON. - Download. Save the formatted or minified result as a text file.
- Share links. Send a teammate a short link like
jsonhero.dev/s/AbC123XyZ0for any valid JSON. The link is copied for you, and you can add a name. See how sharing works.
Open the diff page, or click Compare in the editor to bring your document with you.
- See what changed. Added, removed and changed values, plus values that changed type (the number
42becoming the string"42"), side by side or as a unified diff. Object key order is ignored. - Cut the noise. Match array items by a key such as
idso a reordered list doesn't read as one big change, or compare arrays as sets. Ignore paths like$.**.updatedAt, allow a number tolerance, and compare strings ignoring case or surrounding whitespace. - Spot breaking changes. A compatibility report flags the changes most likely to break code that reads the data.
- Find your way around. Search both documents at once, filter the list of changes by path, and fold unchanged lines.
- Load each side your way. Paste it, drop or open a file, or fetch it from a URL.
- Share a comparison. One link opens both documents with your rules and the view you were on.
- Export a comparison as a JSON Patch, a unified diff or Markdown (Pro).
Works in current versions of Chrome, Firefox, Safari and Edge.
| Shortcut | Action |
|---|---|
| Ctrl/Cmd + Shift + M | Minify (editor) |
| Ctrl/Cmd + F | Jump to the search box (replaces the browser's find) |
| Enter / Shift + Enter | Next / previous search match |
| Ctrl/Cmd + Enter | Previous search match in the editor; run the comparison on the diff page |
| Esc | Close a dialog or menu |
Formatting, minifying, validating, searching, folding, unescaping, comparing and downloading all run as JavaScript in your browser. None of them upload your JSON or send it to analytics.
Share is the one exception. It uploads the editor contents, or both documents when you share a comparison, so the link has something to serve.
- Anyone with the link can open it. Links aren't password-protected; their only protection is a random 10-character id.
- When a link is pasted into Slack, X, Discord or another app that unfurls links, the preview shows the start of your JSON, or for a comparison, the two names and the first few changes, values included.
- When someone opens a link, Google Analytics records the page title: the share's name or, if it has none, its summary (a document's top-level keys, or a comparison's names and change counts). The link itself is never sent.
- Shares are stored without your name or account, even when you're signed in.
- A link lasts 7 days on the free plan or 30 days on Pro. After that it stops working and the stored JSON is deleted.
- Don't share credentials, access tokens or personal data.
What's stored, what the analytics record, and how to check all of this yourself in DevTools: PRIVACY.md.
| Free | Pro | |
|---|---|---|
| Format, minify, validate, search, unescape, compare | ✓ | ✓ |
| Document size | 100 KB | 1 MB |
| Share link lifetime | 7 days | 30 days |
| New share links | 30 an hour, 100 a day | 100 an hour, 500 a day |
| Comparison rules | 1 match key, 3 ignored paths | 50 match keys, 200 ignored paths |
| Saved rule presets | – | Up to 20, in your browser |
| Export a comparison (JSON Patch, unified diff, Markdown) | – | ✓ |
| Support | Priority email | |
| Price | Free | ₹99/month or ₹999/year in India $4.99/month or $49/year elsewhere |
Prices include taxes, and Pro needs an account. The size limit covers pasting, opening a file, fetching a URL, sharing and each side of a comparison. A share link someone sent you opens on any plan, whatever its size.
- Found a bug? Open a bug report.
- Have an idea? Request a feature.
- Security issue? Please report it privately. See SECURITY.md.
- Account, billing, or removing a share link early? Email hello@jsonhero.dev.
Issues here are public, so please don't paste private JSON or share links you want to keep private.
This is the public home of jsonhero.dev: documentation, the changelog and the issue tracker. The app's source code is not published here.
If jsonhero.dev saves you time, starring this repo helps other developers find it.
jsonhero.dev is an independent project built and run by Akash Kumar.