Prove it existed. Without showing it.
Your browser fingerprints the file with SHA-256; the file itself never leaves your device. Only the fingerprint is sealed, into a receipt anyone can check, offline, forever.
or paste text
SHA-256 fingerprint · computed in this browser
The console opens with this fingerprint in place. Sealing costs one tick, one cent; new accounts receive 25 free once the email is confirmed.
Save as Proof, from any page.
Drag the button to your bookmarks bar. Select text on any HTTPS page, click the bookmark, and your browser creates the fingerprint before the console opens with it in place. The selected text is never sent to us.