The Code Formatter That Never Uploads Your Code — 100% Private

Not all code is safe to upload. Business logic, API keys accidentally left in code, proprietary algorithms, code under an NDA — there are many situations where you need to format code without the risk of it being sent to a third-party server. Most online tools upload your code to process it. This one doesn't.

This page explains how our browser-based code formatter keeps your code private, how that works technically, and why it matters.

How Local Processing Works — The Technical Explanation

The formatting engine runs entirely inside your browser using WebAssembly (Wasm). When you paste code and click Format:

1. Your code is passed to the Prettier Wasm module running in your browser's JavaScript engine
2. The formatter processes it entirely within your browser's memory
3. The formatted output is returned to the page — still in your browser
4. Zero bytes of your code leave your device at any point

There are no server requests, no API calls, no logging of code content, no telemetry. We can't see what you format because we technically never receive it. Open your browser's network inspector and you'll see no requests sent when you click Format — only the initial page load.

When Code Privacy Matters Most

Most code formatting is low-stakes. But there are situations where it matters:

• Proprietary business logic — source code for a product you're building or maintaining
• Code with embedded secrets — if someone left an API key or database credential in the code (it happens), uploading it to a server is a security risk
• Client work under NDA — you may have contractual obligations not to share client code with third parties
• Healthcare and financial applications — HIPAA, PCI-DSS, and similar regulations may restrict where data can be sent, even if it's code
• Government or defense contracting — many contracts prohibit sending code to external services

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How We Compare to Other Online Formatters on Privacy

Not all online formatters are equal on privacy:

Formatter type	How it works	Code leaves device?
Server-side formatters	POST your code to their API, format on their server, return result	Yes
CDN-served formatters	Loads formatter from CDN, runs in browser	No (if truly client-side)
This tool	Prettier Wasm runs entirely in your browser	No

The safest approach: use a browser-based tool where processing happens in-browser, and verify by checking the network tab of your browser's DevTools while formatting. You should see no outbound requests containing your code.

Other Developer Tools That Process Locally

The privacy principle applies across our other developer tools as well. None of them upload your data:

• Code minifier — minifies JS/CSS/HTML in your browser, no upload
• Code diff viewer — compares code snippets locally
• JSON formatter — formats and validates JSON locally
• SQL formatter — formats SQL queries locally
• Regex tester — tests expressions locally

When you're dealing with sensitive data, browser-based tools are the right choice. See our private code minifier guide for the minification equivalent of this.

Frequently Asked Questions

How can I verify that my code isn't being sent anywhere?

Open your browser DevTools (F12), go to the Network tab, then paste and format code. You'll see no outbound requests containing your code — only the initial asset loads when the page first opened.

Is this safe for HIPAA-compliant environments?

Since no data is transmitted, this tool does not create a HIPAA compliance issue for code formatting. However, if the code itself contains protected health information (which would be unusual), your organization's security policies should guide tool selection.

Does it store my code between sessions?

No. The textarea content is not persisted. When you close the tab or refresh, the content is gone. Nothing is saved to localStorage, cookies, or any server.