Can Bitcoin be counterfeited?

No, bitcoin cannot be counterfeited on the Bitcoin network in the way paper money can. A bitcoin balance is an entry on a public ledger that many independent computers check, and any attempt to create coins from nothing or spend the same coins twice is rejected. The real risk is fake "bitcoin" sold outside the network.

Can you copy bitcoin or duplicate it?

There is no bitcoin file to copy. Bitcoin.org describes the blockchain as a shared public ledger that records confirmed transactions, which lets wallets work out spendable balances and lets the network check that a sender owns the coins they are spending.

Ownership is proven with a private key. Each transaction carries a signature that proves it came from the owner and cannot be altered after it is issued. Copying a wallet app or its data does not create new coins. It only copies access to the same ones, which is why a leaked seed phrase is dangerous.

The Bitcoin white paper framed the core problem as preventing double spending without a central mint. Its answer was to broadcast transactions publicly and have the network agree on a single history. Our guide to double spending explains this in more detail.

Why can't bitcoin be faked on the network?

The Bitcoin Wiki explains that full nodes download every block and transaction and check them against the consensus rules. Among those rules:

• Blocks may only create a set number of new bitcoin.
• Transactions must carry correct signatures for the coins being spent.
• Within one chain, an output cannot be spent twice.

If a block breaks these rules, the Wiki says it is rejected, even if every other node on the network accepts it. Miners can choose which transactions to include, but they cannot change the rules nodes enforce.

The white paper adds an economic argument. Rewriting history would require redoing the proof-of-work for a block and every block after it. An attacker with that much computing power would likely earn more by following the rules. The scenario where someone controls most of the hashrate is covered in what is a 51 percent attack.

What is fake bitcoin?

Fake bitcoin exists, but outside the Bitcoin network. Exchange Bitvavo's help center describes fake token scams where criminals create tokens that imitate real cryptocurrencies and spread them through phishing sites, fake airdrops and fake recovery services. These tokens usually cannot be sold, and some are built to drain wallets that interact with them.

Bitvavo's suggested checks include comparing the token's contract address with the official one, looking at holder counts and trading activity, and watching for names with small typos.

Coins that split off from Bitcoin through a fork are a different matter. They run on their own ledgers under their own names and are not counterfeit bitcoin. See Bitcoin vs Bitcoin Cash for one example.