Canonical bridge

Polygon Portal

Polygon Portal is the official app for the bridge between Ethereum and Polygon PoS. Deposits to Polygon usually take a few minutes. Withdrawals to Ethereum wait for the next checkpoint, which typically takes from about 45 minutes to a few hours, and then need a claim on Ethereum.

Official website

How it works

1To deposit, you lock ETH, POL or a token in the bridge contracts on Ethereum. Polygon validators see the deposit and credit the same amount on Polygon.
2To withdraw, you burn the tokens on Polygon. Validators regularly post a checkpoint of Polygon's state to Ethereum.
3Once your withdrawal is included in a checkpoint, you claim the funds on Ethereum, paying Ethereum gas.

Trust model

Polygon PoS is a separate chain secured by its own staked validators, not a rollup. You trust that set of validators to sign honest checkpoints, and the bridge contracts that can be upgraded by Polygon governance.

Strengths

The original, most-used way in and out of Polygon PoS, with no third-party liquidity.
Withdrawals take hours, not the 7 days of optimistic rollups.
No bridge fee beyond network gas.

Limitations

Security depends on Polygon's validator set rather than on Ethereum itself.
Only connects Ethereum and Polygon PoS.
You need ETH on Ethereum to claim a withdrawal.