On-chain
On-chain means that a transaction, piece of data, or action is recorded on a blockchain. That record remains part of the data on that blockchain.
What does on-chain mean?
A blockchain is a shared digital ledger. Someone first sends a signed instruction to the network. The network checks it according to its rules. The transaction can then be added to the blockchain.
A record like this can change, for example, the balance of an address or the owner of a token. On public blockchains, transactions and addresses can often be viewed with a block explorer, a search tool for blockchain data. Which data is visible varies by blockchain.
An example of on-chain
You send bitcoin from your own crypto wallet to someone else's address. Once the transaction is recorded on the Bitcoin blockchain, it's an on-chain payment.
An internal transfer between two customers of the same crypto exchange may only appear in that exchange's records. In that case, the transfer doesn't have to be on-chain.
Why does on-chain matter in crypto?
On-chain data helps users verify recorded transactions without relying only on an intermediary. You often pay network fees for an on-chain transaction. Processing times vary by network.
In discussions of on-chain analysis, people examine blockchain data such as transaction flows, active addresses, or smart contract usage. Smart contracts are programs on a blockchain that can automatically carry out agreed actions, for example, when exchanging or lending tokens.
On-chain data doesn't automatically tell you who is making a transaction or why. An address isn't the same as a person. On-chain transactions are also generally difficult to reverse: using the wrong address or a malicious smart contract can lead to losses.
