What never leaves this device?

Document bytes, filenames, page text, and form values are not sent to pdfonbrowser.com for merge, split, compress, convert, redact, OCR, or GST invoice generation. Those jobs run in the tab.

After the app has loaded, yes. Disconnect the network and compress, merge, or redact still run. A tip payment cannot. The file is already yours either way.

How PDF tools run in this tab without uploading the file

Q: What still uses the network?

Static JavaScript and WebAssembly assets when the page loads, optional Google Analytics 4 if a measurement id is configured, and Razorpay checkout only if you tip after a download. Skip never creates a charge.

WebAssembly and JavaScript process merge, compress, redact, and GST invoices on this device. What never leaves, and what still uses the network.