NotChanged proves a PDF came from a real HTTPS website and hasn't changed since you downloaded it. Anyone can verify at notchanged.com.
Download proofs
When you download a PDF from an HTTPS site (a bank, HMRC, payroll portal…), NotChanged records the hostname and SHA-256, then saves a stamped -verified.pdf with a QR verify badge. Lenders upload that file to verify.
Where the NotChanged QR badge is drawn on stamped PDFs.
Advanced
Leave empty for automatic (notchanged.com when available).
Permissions, briefly
Downloads / all sites: to re-fetch the PDF you just downloaded (including PDFs behind a login) and save the stamped copy.
Local files: optional. Turn on "Allow access to file URLs" in chrome://extensions so we can read a download from disk when the site's link was one-time.
Only the PDF you prove and the details you choose to add are sent to NotChanged. PDFs are not stored — only their fingerprint and the signed record.