How to Verify Your Files Are NOT Uploaded to the Internet
Learn to verify with your own eyes that an audio converter is truly private. Step-by-step technical guide using your browser's DevTools.
Quick Answer
Open your browser's DevTools (F12), go to the "Network" tab, filter by method:POST, and convert a file. If you see 0 requests, your files stay on your device.
Recommended filter:
method:POST -url:/stats/This filter shows only file uploads (excludes analytics)
Verification in 4 Steps
Open DevTools
In Chrome/Edge/Firefox: press F12
In Safari: Developer → Show Web Inspector
You'll see a panel at the bottom or right side of your browser.
💡 Universal keyboard shortcut: F12 (Windows/Linux) or Cmd+Opt+I (Mac)
Go to Network Tab
Click the "Network" tab in the DevTools panel.
You'll see all HTTP requests your browser makes. This is normal - the browser downloads JavaScript files, CSS, images, etc. to load the page.
⚠️ IMPORTANT: Seeing GET requests (page downloads) is completely normal. Only POST/PUT requests upload data.
Filter Uploads Only
In the Network tab filter box, type:
method:POST -url:/stats/This filter shows ONLY requests that upload data (POST/PUT) and excludes privacy-respecting analytics.
Then, clear the log by clicking the trash icon (🗑️) to start from scratch.
Convert and Verify
- 1.Select an audio or video file
- 2.Click "Convert to MP3"
- 3.Watch the Network tab DURING conversion
✅ If you see 0 requests = Your files are NOT uploaded
Processing happens 100% in your browser, with no external servers.
Why Does This Work?
WebAssembly in the Browser
PrivAudio uses FFmpeg compiled to WebAssembly (WASM). This means processing happens INSIDE your browser, not on a remote server.
❌ Traditional Converters
Send your file to a server (like mailing a letter)
✅ PrivAudio
Processes on your device (like making a photocopy at home)
What Requests Are Normal?
When you open PrivAudio, the browser downloads:
- •JavaScript files (.js) - The application code
- •CSS files (.css) - Visual styles
- •Fonts (.woff2) - Typography
NONE of these requests upload your file.
Only POST, PUT, or PATCH requests upload data. That's why we filter by method:POST - to see ONLY uploads.
Frequently Asked Questions
What about analytics requests?
Good observation! PrivAudio uses Plausible for analytics (privacy-respecting), which sends small POST requests. But notice the size:
- Plausible request: 500 bytes (just metadata: "user converted file")
- Your file: 50,000,000 bytes (50 MB)
Difference: 100,000 times smaller. Analytics does NOT include your file.
That's why the -url:/stats/ filter excludes analytics and shows only actual file uploads.
Can I do this on mobile?
DevTools requires a desktop browser. On mobile, verify with data usage:
- Turn on airplane mode (WiFi and mobile data off)
- Convert a file in PrivAudio
- If it works = not uploading anything to the internet ✅
Note: First time you need a connection to load the app, but after that it works offline.
Do all browsers have DevTools?
Yes. Chrome, Firefox, Edge, Safari, and Opera include DevTools natively. Universal shortcut: F12 (Windows/Linux) or Cmd+Opt+I (Mac)
How do I know if other converters upload files?
Repeat these same steps on any online tool. If you see POST requests with "Request Size" = your file size, it means they're uploading to their server.
Example: If your file is 45 MB and you see a 45.2 MB POST request, that converter IS uploading your files.
Try It Yourself
Now that you know how to verify privacy, check that PrivAudio delivers on its promise.
Convert a File NowDon't take our word for it - the code is open for your inspection. 🔍