Sealed · I called it
Call it now.
Prove it later.
Write down a prediction and seal it. When it comes true, reveal it, with public proof that you wrote those exact words on that date and never changed them.
Your words never leave this device. Only a fingerprint of them is sent to public timestamp servers. Just for bragging rights: no bets, no money.
Your seals
Kept in this browser only. Download each receipt; if you clear your browser and lose the links, nobody can reveal them, not even us.
How it works
Before you reveal, you can share a sealed version that proves the date but keeps the words hidden. We store nothing: your seal lives in your links and your receipt file.
Open a Sealed receipt to get its links back.
Honest promises
The proof shows your words existed before a particular Bitcoin block was made. It can't show what was in your head, and it can't stop someone from sealing many different guesses and only revealing the one that came true. If someone's reveal looks too lucky, ask to see their other seals.
You can check any reveal without trusting us: download its proof files and drop them into opentimestamps.org.