ZeroUpload converts your files without ever uploading them. That's the whole pitch, and the name is a promise I take literally.

It started with a small thing that annoyed me. I went looking for a free converter, and every site wanted me to upload my file to its servers first. I was about to send a personal document to some company I'd never heard of just to change its format. That's backwards. Your files are nobody's business but yours, and there was no good reason a quick conversion had to involve a stranger's computer.

So I built this on one rule I won't bend: your files never leave your device.

How it actually works

Your browser is a lot more capable than people give it credit for. Using the Canvas API and WebAssembly (the same kind of engine that runs desktop software), ZeroUpload does every conversion right there inside your browser, on your own processor and memory.

Your file gets read off your device, transformed in memory, and handed back to you as a download. It never crosses the network. There's no upload step, no queue, and nothing sitting on a server for me to store, read, or accidentally leak. Even the AI tools, like the background remover, work this way: the model downloads to your browser once, and your image stays put.

What that gets you

  • Real privacy. I can't read your files, because I never receive them. There's nothing to read.
  • It runs on your device, provably. The converting happens in your browser, not on a server — load a page, pull your internet, and it still converts. That's proof nothing is uploaded, not a marketing line. (You do need internet to open the page.)
  • Free, no sign-up, no limits. There are no server bills to cover, so there's no paywall, no "2 free conversions then pay", and no account to make.
  • Fast. Nothing to upload and download again, so it's basically instant.

The promise

I will never add a feature that uploads your files. If that ever changes, the name stops being true, and that's the line. Don't take my word for it, though: open your browser's Network tab while you convert something and watch for upload requests. You won't find any.

Say hi

Got a question, a bug, or an idea for a tool you wish existed? Email me at support@zeroupload.app. I read everything.

— Adham

Founder & builder of ZeroUpload