Most PDF editors just overlay text boxes. CrabPDF modifies the actual text inside the file. Nothing leaves your computer... no server, no account, works offline.
If this is implemented fully in the browser, the file wouldn’t actually be uploaded anywhere. Modern browsers can read local files via the File API and process them with JS/WebAssembly.
One way to verify is to open the Network tab in DevTools and see if any requests are made when editing the PDF.
That’s exactly why I suggest installing it as a PWA and then disabling network access on the PWA. In my opinion, that’s actually the best way to use it.
Interesting approach. I think even if you assure that it is not in the cloud, most people will associate uploading something to the web-browser as being in the cloud, may be a tough hurdle. Cool idea however, nice work!
One way to verify is to open the Network tab in DevTools and see if any requests are made when editing the PDF.
That’s exactly why I suggest installing it as a PWA and then disabling network access on the PWA. In my opinion, that’s actually the best way to use it.