This is a small, plain guide to the smallest piece — the satoshi — and to Lightning, the network built to move it around a cent at a time.
A satoshi — "sat" for short — is the smallest unit bitcoin's protocol can currently record: one hundred-millionth of a single bitcoin.
Named for Satoshi Nakamoto, bitcoin's pseudonymous creator, the unit exists so that people don't have to talk in long decimals. "0.00000500 BTC" is awkward to say, read, or reason about. "500 sats" isn't.
Thinking in sats also changes how an amount feels. A bitcoin is expensive; a sat is not. That makes the unit a better fit for tips, small purchases, and the kind of everyday payment this page is built around: a donation, not an investment.
Bitcoin's base layer is deliberately slow and public — every transaction is confirmed by the whole network and written down forever. That's the wrong tool for a payment worth a few cents.
Lightning is a second layer built on top of bitcoin for exactly that case. Two parties open a private payment channel, move sats back and forth inside it as many times as they like, instantly and for a fraction of a cent, and only touch the base layer to open or close the channel. Route through a few connected channels and you can pay anyone on the network, not just people you've opened a channel with directly.
A Lightning Address is what makes this usable day to day — it looks and works like an email address (name@wallet.com), but behind it sits a Lightning wallet ready to receive. No QR-scanning required to hand someone your address; you can just say it.
1 BTC = 100,000,000 sats, fixed by the protocol — this conversion never depends on price.
1024 is two to the tenth power — the same doubling that gives "kibi-" its meaning in a kibibyte (KiB). It's also this page's donation amount.
There will only ever be 21 million bitcoin, which puts a hard ceiling of 2.1 quadrillion sats on the unit — no more can ever be created.
The first documented real-world bitcoin purchase was two pizzas, paid for with 10,000 BTC — a trillion sats, at a time when that amount bought dinner.
A Lightning payment typically settles in under a second, whether it's crossing the street or crossing the planet.
Satoshi Nakamoto's identity has never been confirmed. The name may belong to one person or several.
No ads, no tracking, no subscription — just a Lightning Address, if you'd like to leave something. 1024 is a suggestion, not a minimum: two to the tenth, the same number this page is named for.