MetaMask bridge: how bridging works inside MetaMask Swaps

Bridging is a swap across networks

MetaMask’s help pages treat bridging — transferring assets between networks — as part of Swaps, on both the extension and the mobile app. You press Swap, select the token you send and the network it is on, select the token you want and the network to receive it on, enter the amount, and review the quote before confirming (MetaMask Help Center). The token on each side does not have to be the same: sending ETH on one network and receiving another token on a second network is the same flow.

Which networks Swaps supports is listed on that help page. The list changes, so we do not copy it here.

What MetaMask does, and what the provider does

MetaMask says that in Swaps it acts as an information aggregator: it pulls quotes together, and you decide whether to proceed with the platform or liquidity provider behind the quote. It does not provide the liquidity, execute the trade, or advise on what to swap. For bridging, it names the sources it uses: aggregators such as LI.FI and Socket, and providers including Across, Relay, the Polygon PoS Bridge and Circle’s CCTP (MetaMask Help Center).

So a bridge “in MetaMask” is still a transfer through a third-party bridge, chosen from the quotes MetaMask shows.

How the fee is made up

MetaMask breaks a Swaps quote into three parts: the quote rate, the network fee (gas to execute the transaction), and a MetaMask fee, which its help page states as a percentage (MetaMask Help Center). Rates change, so the figure is not repeated here. To judge a quote, compare what you would receive on the destination network with what other routes deliver for the same transfer; the comparison on this site shows each provider’s quote for one route and explains how fees are counted, including our own, on the methodology page.

Connecting MetaMask to a bridge’s own site

MetaMask’s bridge guide describes the other way: open a bridge that handles your combination of networks and token, connect MetaMask, choose the networks and asset, and sign. You may be asked to approve a token first, and MetaMask asks you to read every transaction and approval carefully. It does not recommend or endorse the bridges it lists there (MetaMask Help Center). What an approval allows is covered in token approvals.

When the tokens have not appeared

A bridge transfer is not instantaneous. Once it completes, switch MetaMask to the destination network, and add the token if it does not show (MetaMask Help Center). For a Swaps transfer that takes longer than quoted, MetaMask says the time shown is an estimate, delays can come from changing network conditions, and in most cases the transfer is delayed and still completes (MetaMask Help Center).