What happens to crypto if the internet goes down?

If the internet goes down, crypto does not disappear. Your coins are entries on a shared ledger, and every node holds its own copy. What stops is the flow of new transactions and blocks between the places that are cut off from each other.

What happens to bitcoin if the internet goes down?

Bitcoin's design already assumes that messages get lost. The white paper says a node that misses a block will ask for it once it sees the next one and notices the gap. It also says nodes can leave and rejoin at will, and on return they accept the proof-of-work chain as the record of what happened while they were away.

A regional outage mostly removes some miners for a while. In January 2022, an internet shutdown in Kazakhstan, which Cambridge researchers estimated hosted up to 18% of global hashrate, cut the hashrate of several large mining pools, The Block reported. The rest of the network kept running. How bitcoin copes when mining power drops is covered in what happens if bitcoin miners stop mining.

What happens to crypto if the internet crashes everywhere at once?

In a wider outage, groups of nodes could carry on separately, each building its own chain. When links come back, the white paper's rule settles it. Nodes switch to the valid chain with the most work, and blocks on the shorter branch are dropped. Transactions in those dropped blocks return to waiting for confirmation, which is one reason large payments wait for several confirmations.

Proof-of-stake networks react differently. Ethereum.org explains that finalizing the chain needs votes backed by two-thirds of staked ETH. If more than a third cannot vote, finality pauses. After four epochs without finality, a mechanism called the inactivity leak slowly drains the stake of validators outside the majority until the rest can finalize again.

Exchanges, wallets that rely on company servers and price feeds would also be out of reach during an outage. The coins themselves would still be on the ledger.

Can you use bitcoin without internet?

Partly. Blockstream Satellite broadcasts the bitcoin blockchain around the clock from satellites covering North America, Africa, Europe and Asia Pacific. Receiving it is free and needs a small dish and a low-cost USB receiver, so a node can stay in sync with no internet connection. Its README says a separate paid API lets users send encrypted messages through the satellites, paid over Lightning.

Other tools use phone networks instead. Decrypt reported in 2023 that Machankura let people in eight African countries send and receive bitcoin from basic feature phones using text menus. Such services still rely on servers that are online somewhere.

To keep your own copy of the ledger, see how to run a bitcoin node. How the network agrees on one history is explained in what is a consensus mechanism.