Your public key is the lock on your bitcoin; only your private key opens it. Most addresses show it for good once you send from them. A large enough quantum computer, or new maths, could one day open a lock on show.

Only the address is sent, to mempool.space, a public website that shows Bitcoin payments. Like any website, it sees your IP address. We never see the address.

Your Bitcoin address

Only an address. Never your 12 or 24 recovery words.

How it works

While you only receive, an address shows just a cover over the lock. Your first send puts the lock itself on the blockchain for good. Taproot addresses (bc1p…) show it from the start.

As far as anyone has publicly shown, nobody can work out the key from a lock made by proper wallet software today, and no large enough quantum computer is known to exist yet.

Bitcoin on an exchange sits at the exchange’s addresses, so this check does not apply.
A wallet usually has many addresses: check each one that holds bitcoin.
Signed a message with the address, for example to show an exchange it is yours? That shows the lock too.
In 2009 and 2010, newly mined bitcoin often went straight to a public key, with no address covering it, so its lock showed from the start. This check cannot see such coins.

Published counts put 5.1M to 8.2M bitcoin behind a lock on show, 25% to 41% of the 20.1M bitcoin mined so far (data to 8 October 2026).

Read the research: Bunker mode

Educational only. Not investment advice. DYOR. Live data: mempool.space. Totals and fee: our Bunker mode research, data to 8 October 2026.