Don't trust us. Verify it.
Data Alias claims your files never leave the browser. That claim would be worthless if you had to take our word for it — so here are three ways to check it yourself, from easiest to most thorough.
Watch the network tab
Open this site, then open your browser's developer tools (F12 or ⌘⌥I) and switch to the Network tab.
Clear the log, then upload a file, review it, create the safe copy, and download it.
Watch the log while you do it: zero requests appear. No upload endpoint, no API call, no telemetry — the entire pipeline runs in your tab.
Go offline
Load this page, then turn on airplane mode or disconnect from Wi-Fi entirely.
Now process a file: upload, review, transform, download. Everything works, because nothing needed a server in the first place.
A tool that uploads your data cannot survive this test.
Read our own audit
Every release runs an automated browser audit that records all network traffic during a complete upload → review → transform → download flow.
The pass condition is exactly zero non-page requests — zero requests carrying file content, filenames, or detected values. A release that fails this check does not ship.
The audit scripts live in the open in our repository (e2e/), so the methodology itself is inspectable.
What we do see — the honest version
- • Loading the page fetches the page itself: HTML, scripts, styles, and fonts — all served from this domain, nothing third-party.
- • If you choose to sign in, the server learns your email and plan. Never your files, cell values, column names, or filenames.
- • Data Alias reduces exposure risk but cannot guarantee detection of every sensitive value. Review the result before sharing it — that review step exists on purpose.