What Does On-Chain Mean?
Any transaction or activity that is recorded directly on the Bitcoin blockchain. On-chain transactions are permanent, publicly visible, and secured by the full network.
Why It Matters
On-chain transactions represent Bitcoin's fundamental strength and core limitation. Every on-chain transaction is permanently recorded in the blockchain. Viewable by anyone. Secured by the full network. Immutable. Cannot be reversed. Cannot be censored.
The tradeoff: on-chain is slow (10-minute block times) and space-limited (about 7 transactions per second). For large transfers, settlement finality, or when you need absolute certainty, on-chain is the right call. For everyday spending, off-chain solutions like Lightning are better. Knowing when to use which matters for making the best use of Bitcoin.
How It Works
On-chain transactions start when you broadcast your transaction to the Bitcoin network. It enters the mempool. Waits for miners. Once included in a block, the transaction is confirmed and permanently recorded. Each subsequent block confirms it further. On-chain is all-or-nothing: either the transaction makes it into a block and becomes part of the permanent record, or it sits unconfirmed and eventually gets dropped from the mempool if fees are too low. Everything is recorded publicly, so all Bitcoin transactions are pseudonymous but not anonymous: with enough analysis, transactions can often be traced.