Polygon Bridge moves supported tokens between Ethereum and Polygon PoS. Before transferring, check the exact token your destination app accepts: tokens with the same ticker can have different contracts on Polygon.

What should you check before you start?

Check the direction, token contract and wallet balance on the sending network. The Polygon token bridge works with mapped assets: an Ethereum token must have a corresponding token on Polygon. A familiar ticker alone does not establish that the token arriving on Polygon is the one your app needs.

For example, suppose you have 100 USDC on Ethereum to use in a Polygon app. Polygon has native USDC and bridged USDC.e, and an app may accept only one of them. Check the app’s listed contract address against the token you expect to receive before you approve a transfer.

You also need gas on the networks where you will sign transactions. Keep ETH on Ethereum for a deposit or final withdrawal claim, and POL on Polygon for a withdrawal or your first transaction after a deposit. Bridging the full balance of a gas token can leave you unable to take the next step.

How do you deposit from Ethereum to Polygon?

A deposit locks the token on Ethereum and credits its mapped counterpart on Polygon, generally at a 1:1 token amount. It does not swap the token or send the original Ethereum contract to another chain. For ERC-20 tokens, the process can require a separate approval transaction before the deposit.

1. Connect the wallet holding the token on Ethereum. Confirm that the destination is Polygon PoS and that the displayed token mapping matches what you need.
2. Enter the amount and review the wallet’s approval request, if one appears. Approval permits a contract to use the specified token; the subsequent deposit is the transaction that moves it into the bridge.
3. Sign the deposit and save its Ethereum transaction hash. Wait for the corresponding balance on Polygon, then check that your wallet is showing Polygon and the expected token contract.

Under the hood, Ethereum’s RootChainManager routes a mapped deposit to a Predicate contract, which locks the tokens. A state sync carries the deposit information to Polygon, where the corresponding balance is credited. That is why an Ethereum confirmation and a visible Polygon balance are separate events.

How do you withdraw back to Ethereum?

A withdrawal starts by burning the bridged token on Polygon, then ends with a claim on Ethereum. Polygon Bridge withdrawals therefore have two transactions on different networks, with a checkpoint between them. A Polygon transaction marked successful means the burn happened; it does not mean the Ethereum tokens are already in your wallet.

1. With POL available for gas, initiate the withdrawal of the mapped token on Polygon. Save the Polygon transaction hash so you can track the exit.
2. Wait for a checkpoint, which commits a record of Polygon blocks to Ethereum. Once the burn is included, a proof can establish that the withdrawal occurred.
3. Submit the claim on Ethereum and pay its gas in ETH. The bridge verifies the proof and releases the locked tokens to your Ethereum wallet.

Do not start another withdrawal because the tokens disappear from your Polygon balance while you wait. Burning them is the expected first step, and the claim remains to be completed on Ethereum. A withdrawal already initiated on Polygon cannot simply be cancelled.

How much time and gas should you allow?

Allow tens of minutes for a typical deposit, though network conditions can extend it. A withdrawal must wait for a checkpoint before the Ethereum claim; checkpoints are generally produced at roughly 30-minute intervals, and delays can make the wait longer. After the checkpoint, the claim still needs an Ethereum transaction.

Gas varies with network demand and the transactions required. As an illustration, an ERC-20 approval and deposit using 200,000 gas in total at 5 gwei would cost 0.001 ETH in Ethereum gas; that is an example calculation, not a quoted fee. A withdrawal also uses POL gas for the burn and ETH gas for the claim, so check the wallet’s live estimates before signing.

Match the receiving token to your app first, then budget for each transaction and the withdrawal checkpoint. The Polygon Bridge lets you move a supported token between Ethereum and Polygon when those checks are done. For a bridge from Ethereum to Polygon, confirm the resulting token balance on Polygon before sending it into your app.