Blog › Privacy

How Vootkit processes your files without ever seeing them

Privacy · 5 min read

A device with no connection to the cloud

"We don't store your files" is a sentence on a thousand websites. The problem is you can't verify it — the file still went to their server, and you're trusting a promise. Vootkit takes a different route: the file never reaches us in the first place. Here's what that actually means, in plain terms.

What a normal online tool does

A typical "online converter" works in four steps: your browser uploads the file to their server, the server processes it, it stores the result, and you download it. Your file sat on a machine you don't control. Whether they delete it, log it, or scan it is entirely up to them — and invisible to you.

What Vootkit does instead

When you open a Vootkit tool, your browser downloads a small program — the tool's code. From that point on, everything happens locally:

You pick a file. It's read straight into your browser's memory from your disk.
The processing engine runs in the page — FFmpeg compiled to WebAssembly for video and audio, the Canvas API for images, PDF.js for PDFs, and the Whisper model for transcription.
The result is written back into memory and handed to you as a download.

At no point does a request carry your file to a server. You can check this yourself: open your browser's developer tools, go to the Network tab, and run any tool. You'll see the tool's code load — and then nothing leaves while it works.

This is the important part: privacy here is structural, not a policy. We can't misuse your file because we never receive it. There's no server-side copy to leak, subpoena, or forget to delete.

What about the AI transcription?

Even the heavy stuff stays local. The Subtitle Generator downloads the Whisper speech model (about 40MB, once) and runs it inside your browser. Your audio is transcribed on your own processor. That's unusual for a transcription tool — most send your audio to a cloud — and it's the entire point.

The trade-offs, stated honestly

On-device processing has real limits. Big files lean on your device's memory, so phones can struggle where a server wouldn't. Some heavy operations are slower than a data centre. And the first use of an FFmpeg or AI tool downloads its engine. We think that's a fair price for files that never leave your hands — and we'd rather name the trade-offs than hide them.

Try a tool →

This article is about how the tools work; for the formal policy, see our Privacy Policy.