How Tabmorph works
Your files are converted inside your browser tab. They’re never uploaded, and you can check that yourself.
Converted on your device
When you open a converter, your browser downloads Tabmorph’s converter code from tabmorph.app: image decoders and encoders, a PDF renderer and a PDF writer. When you add a file, that code reads it from your disk, converts it in memory and hands the result back as a download. No server is involved in converting.
Check it yourself
The Wi-Fi test: open a converter, wait a moment, then turn off Wi-Fi or unplug your network. Convert a file. It still works, because nothing needs to be sent.
The Network tab: open your browser’s developer tools (F12, or ⌥⌘I on a Mac), choose Network, and convert a file. You’ll only see the converter loading its own code from tabmorph.app. No request contains your file.
The counter: the bar at the bottom of the converter counts every network request the converter made since you added files, including from its background workers.
Why the converter runs in a frame
The page you’re reading lives on tabmorph.com. The converter box is a separate site, tabmorph.app, shown inside it. Browsers keep different sites apart, so code on this page can’t reach into the converter and read your files. Files can only be added inside the box, and the converter sends nothing back to the page. The converter site loads no third-party code at all, and its security policy only lets it load its own files.
Prefer it on its own? Every converter has an “Open in its own tab” link that opens tabmorph.app directly.
Built on open-source software
Tabmorph uses well-known open-source libraries, such as libheif for iPhone photos and Mozilla’s pdf.js for PDFs. See the licenses page.