Withdrawing back to Ethereum
Native Bridge
The native bridge is also slower than other bridging protocols when it comes to withdrawals. However, it is the safest and most trustless way to move funds from Frame back to mainnet. Once a valid withdrawal is submitted, it is impossible for any party to stop the transaction from completing. 1
The full withdrawal process using the native bridge will take about 8 days for mainnet, and 30 minutes for testnet. Once a withdrawal is initiated on Frame, a dispute window (8 days on mainnet, 13 minutes on testnet) is opened to allow honest parties to challenge the validity of the withdrawal. After 8 days with no challenge, the user who initiated the withdrawal can claim their ETH through the bridge.
Using the native bridge incurs no extra fees beyond the standard transaction gas fees.
Fast Bridges
Fast bridges can process withdrawals within 30 minutes, but charge a small fee to front the Ether to users. As we get closer to mainnet, we'll reveal which fast bridges will be available upon launch.
These bridges will wait for L2 finality (transaction ordering finalized by the data availablity layer) before processing the withdrawal.
Fast bridges usually start a withdrawal through the native bridge which deducts from the user's balance. They then promptly send ETH to the user and later claim the bridged ETH following the challenge window (~8 days on mainnet).
1: This assumes that the L1 bridge contract is non-upgradeable.