What the chain shows about you

Bitcoin is public, not anonymous. The record never shows names, but every address, amount and time is visible to anyone, forever. Once one of your addresses is tied to you, the record can show a lot about where your coins came from and went.

What anyone can see

Give someone an address and they can look it up in any block explorer. They will see every payment that address has received and sent, when, and how much it holds now. They can follow the coins one step further to the addresses they came from or went to.

Live from the chain

An address everyone knowsLoading live figures…

Holds now

…

Payments in and out

…

Separate pieces

…unspent outputs

The Internet Archive lists this address on its donation page, so every gift sent to it, large or small, is visible to everyone. For an organization collecting donations that openness is the point. For a person it usually isn't.

See it on satoshis.watch →

How addresses get linked

Reuse	Receiving many payments at one address puts them all in one place that anyone can look up.
Spending together	When a transaction spends several pieces at once, they were most likely held by the same wallet, so analysts usually treat them as one owner.
Change	The change output often gives itself away, for example by its type or its uneven amount, so the next step can be followed too.
Exchanges	Most exchanges check your ID. They know which addresses you withdrew to and deposited from, and in many countries they must report to the authorities.
Posting it	An address written beside your name on a website, invoice or social post is linked to you for good.

None of these needs special access. Companies sell software that applies them to the whole chain, and police and tax agencies use it. That is how many thefts and scams have been followed after the fact.

Habits that reveal less

• Let your wallet hand out a new address for each payment. Most do this by default.
• Don't post an address with your name unless you want its whole history public.
• Be careful about whom you show your balance to. Knowing that someone holds a lot of bitcoin can make them a target.
• Some wallets let you choose which pieces to spend, so unrelated coins aren't combined.

How this shows up when you look up an address: address reuse, explained on satoshis.watch.

Payments over Lightning, covered in its own lesson, don't put each small payment on the chain, which also keeps them out of the public record.