Bitcoin, Start Here

Updated 2026-10-29

Short answer: Bitcoin is the first and largest cryptocurrency, with a fixed supply of 21 million coins. It does one thing, moving BTC between people without a bank, and it's built to change slowly. A new block comes about every 10 minutes, fees rise when the network is busy, and a transaction can't be reversed once it's confirmed.

Addresses

Bitcoin addresses come in a few styles, and they can all send to each other:

bc1q… and bc1p… (the modern ones, with lower fees),
3… and 1… (older styles, still valid).

Many wallets show you a new receiving address each time. That's normal and helps your privacy; every old address still works. It does mean your coins can sit on several addresses, so to see them all in our Portfolio, add each address you've received to.

Fees and waiting

You pay a fee to the miners, set by how much space your transaction takes, not by how much BTC you send.
When the network is busy, fees rise. Most wallets let you pick a slower, cheaper option.
Wait for a few confirmations (blocks) before treating a large payment as final.

Watch out

Never send other coins to a Bitcoin address (or BTC to an address on another chain). "Wrapped" bitcoin tokens on other chains, like WBTC or BTCB, are not BTC on the Bitcoin network.
"Bitcoin doubling" and giveaway scams are as old as Bitcoin. Nobody sends back more than you send.
Keep your seed phrase offline. See seed phrases and hardware wallets.

On Crypto Lighthouse

[Portfolio](/portfolio): add a Bitcoin address to see its BTC and value.
[Check an Address](/check): see whether an address has been used and whether it's on the U.S. sanctions list before you send.

Learn more at bitcoin.org.