Why the route in is cheap and the route out is slow
Optimism’s Standard Bridge moves funds from Ethereum in minutes, while a withdrawal back to Ethereum completes only after a seven-day challenge period — the window in which a fault proof can dispute it (Optimism documentation). Nothing similar applies coming in, so on routes to Optimism the difference between the quotes above comes from the providers themselves. The table shows what each one would actually deliver, not what it advertises.
Native USDC and USDC.e are different tokens
Circle issues native USDC on Optimism; USDC.e is the older token bridged from Ethereum and is not issued by Circle (Circle). A wallet can hold both at once and show two lines with the same name. Exchanges credit deposits only for the token they list, so it is worth checking which one a route delivers before sending a large amount. The quotes here use native USDC.
Gas on Optimism is paid in ETH
Optimism lists ETH as the currency of OP Mainnet (Optimism documentation), so a stablecoin balance that arrives alone cannot be moved again until a little ETH arrives too. A transaction fee there has three parts: an execution gas fee, an L1 data fee and an operator fee (Optimism documentation). The gas figure in the table is what the transaction costs on the network you send from.
The exchange row
If the funds are already on an exchange that supports Optimism for that token, withdrawing directly skips the source-network transaction. That row appears beside the bridges whenever we have the data, including when it is the cheaper option; it excludes deposits to the exchange, trading fees and account requirements.
Questions
How do I bridge to Optimism?
From Ethereum, the Standard Bridge delivers within minutes; from other networks, a third-party provider does the same job at its own price. Compare what each would deliver for your token and amount.
How long does a USDC transfer to Optimism take?
Into Optimism nothing holds the transfer back, so the time is the provider's own estimate, shown in the Time column. Out of Optimism through the official bridge, a withdrawal completes only after a seven-day challenge period.
How do I send USDC to MetaMask?
OP is one of the networks MetaMask supports; if it is not already switched on, add it from "Additional networks" in the network selector. A token shows only once its contract is added or detected. Note which USDC you are sending: native and bridged USDC.e are separate tokens on Optimism.
Sources
- Optimism documentation — using the Standard Bridge · checked 2026-09-12
- Optimism documentation — connecting to OP Mainnet · checked 2026-09-14
- Optimism documentation — transaction fees on OP Mainnet · checked 2026-09-14
- Circle — what you need to know: native USDC on OP Mainnet · checked 2026-09-12
- MetaMask Help Center — how to add a network · checked 2026-09-13