Your text never leaves this device
The diff algorithm is JavaScript that runs in your browser tab. When you press Compare, the two versions are held in memory, compared, and rendered. No network request carries your content.
Privacy
Comparisons happen in your browser, not on our servers
Redline is designed for contracts, source code and unreleased drafts. That only works if the content stays with you.
Uploads are read locally
Choosing a file uses the browser's FileReader API. The file is read from disk into the page — it is not sent to Redline or to any third party.
Nothing is stored
There is no database of comparisons and no shareable-link storage in this version. Close or refresh the tab and the text is gone.
No account, no tracking pixels
The core tool has no sign-up wall. There are no advertising trackers embedded in the diff view.
How to verify this yourself
Open your browser's developer tools, switch to the Network tab, and run a comparison. You will see no request carrying your text. You can also disconnect from the network entirely — the tool keeps working.