On-chain vs off-chain explained
- Author
- CRYPTO PORT Editorial
- Published
- Updated
- Reading time
- 5 min
In short
On-chain means recorded on the blockchain; off-chain means handled outside it. Trades inside an exchange are off-chain, while a withdrawal is on-chain. Which side an action happens on determines what record exists and whether it can be undone.
Key points
- On-chain records are public and independently verifiable
- Off-chain records live in an operator's own books
- Trades inside an exchange never touch the chain
- On-chain transfers generally cannot be reversed
Definition
A distinction between activity executed and recorded on a blockchain, and activity handled outside it that leaves no ledger record.
Buying bitcoin on an exchange leaves nothing on the blockchain — the operator simply updates numbers in its own system, which is why it is fast and cheap. Only when you withdraw to your own wallet does an on-chain transfer occur, with its fee and confirmation wait.
The distinction shapes what record exists. On-chain transactions sit in a public ledger anyone can inspect: sender, recipient, amount and time persist permanently, so activity is pseudonymous rather than private. Off-chain records exist only with the operator, and may become unverifiable if that operator fails.
Hybrid designs such as Layer 2s and state channels do the work off-chain and settle results on-chain. How much to move off-chain — and which assumptions you accept in exchange for the speed and cost — is the central design question.
Watch out for
- · An exchange balance is an entry in its books, not an on-chain asset
- · An on-chain transfer to the wrong address cannot be recalled
- · Ledger records are permanent, so reusing addresses links your history together