JSON Formatter Pro
A developer’s best friend for working with JSON. Format, validate, and explore JSON directly in your browser – no need to copy-paste into external tools.
JSON Formatter Pro is a free, open source Chrome extension that automatically detects and formats JSON responses in your browser tabs. Collapsible tree view, syntax highlighting, and raw/formatted toggle make working with APIs effortless.
Install Free from Chrome Web Store View Source on GitHub
Why JSON Formatter Pro?
If you work with REST APIs, webhooks, or any service that returns JSON, you have probably stared at a wall of unformatted text in your browser. JSON Formatter Pro fixes that automatically. Open any URL that returns JSON, and it is instantly formatted with a clean, interactive tree view.
No setup required. No accounts. No data sent anywhere. It all happens locally in your browser.
Key Features
- Auto-detection – Automatically identifies JSON responses and formats them on page load
- Collapsible tree view – Expand and collapse nested objects and arrays to explore complex structures
- Syntax highlighting – Color-coded keys, strings, numbers, booleans, and null values
- Raw/Formatted toggle – Switch between the formatted view and raw JSON with one click
- Copy to clipboard – Copy the entire JSON or any subtree with a single click
- Valid JSON indicator – Instantly see whether the JSON is valid or contains errors
- Dark mode support – Comfortable viewing that follows your system or browser preferences
- Zero permissions abuse – Only activates on pages that actually contain JSON
- Multilingual support – Available in English, Spanish, French, German, Japanese, Portuguese, and Chinese
Built for Developers
JSON Formatter Pro is designed with the developer workflow in mind:
- API development – Inspect API responses directly in the browser without switching to Postman or curl
- Debugging – Quickly navigate deep JSON structures to find the data you need
- Code reviews – Verify JSON payloads and configuration files in browser-based tools
- Learning – Explore public APIs with a clear, readable view of the data they return
Privacy and Security
JSON Formatter Pro processes everything locally in your browser. It does not:
- Send your JSON data to any server
- Track which URLs you visit
- Collect analytics or usage data
- Require network access of any kind
The source code is fully available on GitHub for review and contributions.
How It Works
- Install the extension from the Chrome Web Store
- Navigate to any URL that returns a JSON response
- View the auto-formatted, syntax-highlighted output
- Explore nested structures by expanding and collapsing nodes
- Copy any part of the JSON tree to your clipboard
That is it. No configuration needed.
Frequently Asked Questions
Does JSON Formatter Pro work on local files?
Yes. You can enable the “Allow access to file URLs” option in Chrome’s extension settings to format local .json files.
Will it slow down my browsing?
No. The extension only activates when it detects that a page contains a JSON response. It has zero impact on normal web browsing.
Can I format JSON that is not auto-detected?
The extension is designed to auto-detect JSON content types. If a server returns JSON with a non-standard content type, the extension may not activate automatically. In those cases, you can use the popup to manually format the page content.
Is it compatible with other developer tools?
Yes. JSON Formatter Pro works alongside browser DevTools and other extensions without conflicts. It formats JSON at the page level, so your DevTools network panel and console remain unaffected.
Does it support JSONP or JSON with comments?
The extension focuses on standard JSON. JSONP responses and JSON with comments (JSONC) may not be auto-detected, but standard JSON from APIs and data endpoints is fully supported.
More Free Chrome Extensions by Zovo
- Tab Suspender Pro – Save memory by suspending inactive tabs
- Cookie Manager – View, edit, and export browser cookies
- Regex Tester Pro – Test regular expressions with real-time highlighting
- Clipboard History Pro – Save and search your clipboard history
JSON Formatter Pro is built and maintained by Zovo. Open source. No tracking. Just clean JSON.