- Fast Transfer: Attestations are issued after the transaction is confirmed and included in a block, typically in seconds. Because of the faster finality time, Fast Transfers are subject to a global allowance to mitigate reorganization risks.
- Standard Transfer: Attestations are issued after hard finality, when the transaction is unlikely to be reversed by a chain reorganization, typically in minutes.
Fast Transfer attestation times
The table below shows the average time for attestations to become available when using Fast Transfer (minFinalityThreshold ≤ 1000):
| Source blockchain | Block confirmations | Average time |
|---|---|---|
| Ethereum | 2 | ~20 seconds |
| Arbitrum | 1 | ~8 seconds |
| Base | 1 | ~8 seconds |
| Codex | 1 | ~8 seconds |
| Ink | 1 | ~8 seconds |
| Linea | 1 | ~8 seconds |
| OP Mainnet | 1 | ~8 seconds |
| Plume | 1 | ~8 seconds |
| Solana | 2-3 | ~8 seconds |
| Unichain | 1 | ~8 seconds |
| World Chain | 1 | ~8 seconds |
Blockchains without Fast Transfer:Some blockchains don’t support Fast Transfer as a source blockchain because
their standard attestation times are already fast. For these blockchains, use
Standard Transfer:
- Arc Testnet
- Avalanche
- HyperEVM
- Monad
- Polygon PoS
- Sei
- Sonic
- XDC
Standard Transfer attestation times
The table below shows the average time for attestations to become available when using Standard Transfer (minFinalityThreshold ≥ 2000):
| Source blockchain | Block confirmations | Average time |
|---|---|---|
| Ethereum | ~65 | ~15-19 minutes |
| Arbitrum | ~65 ETH blocks | ~15-19 minutes |
| Arc Testnet | 1 | ~0.5 seconds |
| Avalanche | 1 | ~8 seconds |
| Base | ~65 ETH blocks | ~15-19 minutes |
| BNB Smart Chain | 3 | ~2 seconds |
| Codex | ~65 ETH blocks | ~15-19 minutes |
| HyperEVM | 1 | ~5 seconds |
| Ink | ~65 ETH blocks | ~30 minutes |
| Linea | 1 | ~6-32 hours |
| Monad | 1 | ~5 seconds |
| OP Mainnet | ~65 ETH blocks | ~15-19 minutes |
| Plume | ~65 ETH blocks | ~15-19 minutes |
| Polygon PoS | 2-3 | ~8 seconds |
| Sei | 1 | ~5 seconds |
| Solana | 32 | ~25 seconds |
| Sonic | 1 | ~8 seconds |
| Unichain | ~65 ETH blocks | ~15-19 minutes |
| World Chain | ~65 ETH blocks | ~15-19 minutes |
| XDC | 3 | ~10 seconds |
Layer 2 finality
Layer 2 (L2) blockchains built on Ethereum publish transaction data in batches to Ethereum Layer 1. The finality characteristics of L2 chains depend on when batches are posted and when those batches achieve finality on Ethereum L1.OP Stack chains
OP Stack-based chains (including Base, OP Mainnet, and World Chain) post
state updates using EIP-4844 blob transactions
approximately every 15 minutes. Circle waits for the Ethereum L1 block
containing the batch to finalize, which typically takes ~65 blocks (15-19
minutes) after the batch is posted.
Linea
Linea has a longer finality period compared to other L2 chains. Standard
Transfer on Linea typically requires 6-32 hours before attestations become
available.
Solana finality
Solana uses a different finality model:Fast Transfer
Circle waits for the block to be confirmed (votes from validators
representing over two-thirds of total stake). This typically takes 2-3
blocks (~8 seconds).
Standard Transfer
Circle waits for block finality, which takes 32 blocks (~25 seconds).