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Blur Document

Don't trust us. Check.

Every tool on Blur Document runs inside your browser, so your files are never uploaded. Here are three ways to see that for yourself, from easiest to most convincing.

1. Run a file and watch the network

Your file goes through the same steps as in the editor: opened, read, checked for personal details, redacted, exported and read again. Meanwhile every request this page makes, and every byte it tries to send, is listed.

Your device is online.

For the strongest test, turn on airplane mode or unplug the internet, then run it.

Drop any file to test with

A photo, scan, screenshot or PDF. It's processed exactly as in the editor, and never leaves this tab.

The list shows this page's own requests. Requests made inside background workers (the text-reading engine fetching its own files) don't appear here, which is why the next two checks matter more.

2. Check your browser's network tab

  1. On a computer, open the editor, then open your browser's developer tools: F12, or Ctrl+Shift+I (Cmd+Option+I on a Mac). In Safari, turn on the Develop menu in Settings first.
  2. Go to the Network tab and tick Preserve log, so nothing scrolls away.
  3. Drop a file, review it and export it.
  4. Look at what was sent. An upload would be a request with your file in its payload, usually a POST or PUT the size of your file. In Chrome and Edge you can type method:POST into the filter box. You'll see downloads of app files only.

3. Turn off the internet and try it

  1. Open the editor (or this page) once while online, so the app is saved on your device.
  2. Switch on airplane mode, turn off Wi-Fi, or unplug the cable.
  3. Drop a file, let it find the details, and export a redacted copy.
  4. It works, because there is nowhere for the file to go. Turn the internet back on when you're done.

Installed as an app (look for Install app in the header, or Add to Home Screen on a phone), it opens and works offline any time.

What the site does connect to

  • This website: the app itself, and the AI and face-detection models.
  • cdn.jsdelivr.net: the open-source text-reading engine (Tesseract) and its English language data. Downloads only.
  • Cloudflare Web Analytics, when enabled: cookieless page-view counts.

Your browser enforces this list. The site's Content Security Policy blocks connections to anywhere else, so even a bug could not send a file to another server. The full details are in the security write-up.

Questions

Why should I believe the monitor on this page?

You shouldn't have to. It's code we wrote, so it's a convenience. The two checks that don't rely on us are your browser's own network tab and the offline test: with no internet connection, nothing can be sent anywhere.

Why does the page download anything at all?

The app, the text-reading (OCR) engine and the AI models have to reach your device before they can run on it. Those are downloads into your browser. Your file goes the other way only if something uploads it, and nothing does.

Does the offline test work on a phone?

Yes. Open this page, switch on airplane mode, then run the test. If the text-reading engine wasn't saved yet, the page tells you to run it once online first. Installed as an app, Blur Document keeps working offline.

Is there any analytics?

Cloudflare Web Analytics may count page views: cookieless, no fingerprinting, and it never sees your files. See the privacy policy for details.