Bitcoin
Bitcoin is the first cryptocurrency and the first blockchain ever created, launched in 2009 by a creator known under the pseudonym Satoshi Nakamoto.
Key feature
Bitcoin is the first cryptocurrency and the first blockchain ever created, launched in 2009 by a creator known under the pseudonym Satoshi Nakamoto.
- Bitcoin uses Proof-of-Work consensus: transactions are grouped into blocks, which are found roughly every 10 minutes.
- Limited supply — only 21 million BTC will ever be issued; no more will ever be created.
- The UTXO model — an address doesn't have a "balance" in the usual sense. Instead, it has a set of unspent transaction outputs (UTXOs), which your wallet adds up for you. When you send funds, an entire output gets spent, and any leftover comes back to you as change. For example, if you have one output worth 1 BTC and you send 0.3 BTC, your wallet spends the whole output: 0.3 BTC goes to the recipient, and the remaining ~0.7 BTC (minus the fee) comes back to you.
- The fee depends on transaction size, not the amount you send. It’s measured in satoshis per virtual byte (sat/vB), so sending $10 or $100,000 can result in the same fee. Size is determined by the number of inputs and outputs—combining many small UTXOs into one payment typically costs more than spending a single large one.
Address formats
Over the years, the network has used several address formats — four are in use today. They all work on the same network and hold the same Bitcoin, but they differ in transaction size, and therefore in fees.
1. Legacy (P2PKH): starts with "1" (e.g. 1AM8n...)
The original format, in use since 2009. Transactions from these addresses are heavier than the rest, making them more expensive to send. Accepted by every service without exception.
2. Nested SegWit (P2SH): starts with "3" (e.g. 3BtK2...)
A middle-ground format: it gets some of SegWit’s savings, but it still looks like an old-style address, so it’s accepted by services that don’t support bc1 addresses. It’s about a quarter cheaper than Legacy. Multisig addresses also start with “3”.
3. Native SegWit (P2WPKH, Bech32): starts with "bc1q"
This is the format Keeper uses by default. The most common format on the network today. Transactions cost roughly 30–40% less than Legacy.
One detail to note: bc1... addresses use a single case. YouzzzzzzZZr wallet accepts both lowercase and uppercase letters, but you cannot mix them within the same address.
4. Taproot (P2TR): starts with "bc1p"
The newest format, introduced in 2021. Slightly cheaper and more private for complex spending scenarios, but for regular transfers the difference from bc1q is small.
Network fee
Bitcoin fees aren't a fixed amount. They're calculated in satoshis per byte (sat/vByte). The heavier the transaction and the busier the network, the higher the fee. Keeper calculates the fee automatically and shows it to you before you send.
📌 During periods of high network congestion, fees can rise significantly. This is a feature of Bitcoin itself.
Confirmation speed
Like on other networks, Bitcoin transactions first enter a queue (the mempool) and wait to be included in a block, but on Bitcoin this takes noticeably longer. On average, confirmation takes about 10 minutes, though for full certainty it's worth waiting for a few confirmations.
If a transaction remains in "Sending" or "Receiving" status for a long time, it isn't stuck. It's just taking longer to confirm than usual. This can happen if network congestion increases after you've sent the transaction, making its fee lower relative to newer transactions competing for block space. The transaction will still confirm, it may just take a few hours.