The Polygon PoS Bridge (Proof of Stake Bridge) is the most commonly used official bridge for transferring assets between Ethereum and Polygon. It leverages the security of Ethereum while providing faster and cheaper transactions on the Polygon network. The PoS Bridge is ideal for everyday transactions, DeFi interactions, and NFT transfers.
How the Polygon PoS Bridge Works
The PoS Bridge operates through a set of smart contracts deployed on both Ethereum and Polygon. When you deposit tokens, they are locked in the Ethereum root contract. The Polygon validators (running the Proof of Stake consensus mechanism) verify this deposit, and equivalent tokens are minted in your wallet on the Polygon side.
For withdrawals from Polygon back to Ethereum, a two-step process is required. First, you initiate the withdrawal on Polygon, which burns your tokens. You then wait for a checkpoint — a Merkle proof of your transaction bundle — to be submitted to Ethereum. This typically takes 2–3 hours. Once the checkpoint is finalized, you can complete the withdrawal and receive your tokens on Ethereum.
Supported Assets on PoS Bridge
The Polygon PoS Bridge supports a wide range of assets including ETH, MATIC (now POL), USDT, USDC, DAI, WBTC, AAVE, LINK, and virtually any ERC-20 token that has been mapped to the Polygon network. NFTs using the ERC-721 and ERC-1155 standards are also supported.
PoS Bridge Transaction Times
Deposits (Ethereum → Polygon): Approximately 7–8 minutes after transaction confirmation on Ethereum.
Withdrawals (Polygon → Ethereum): 2–3 hours, due to the checkpointing process to Ethereum mainnet.
PoS Bridge vs Plasma Bridge
Polygon originally offered two bridges: the PoS Bridge and the Plasma Bridge. The Plasma Bridge uses Plasma technology for high security but is limited to specific tokens (MATIC, ETH) and has a 7-day withdrawal period. The PoS Bridge supports many more tokens with much faster withdrawals (2–3 hours), making it the preferred choice for most users. Polygon Bridge V2 is based entirely on the PoS chain.
Security of the PoS Bridge
The PoS Bridge is secured by the same validator set that secures the Polygon PoS chain. These validators stake MATIC/POL tokens as collateral — this collateral can be "slashed" (forfeited) if validators act maliciously. The official bridge is generally the safest route for large amounts because it avoids the liquidity risks associated with third-party bridge protocols. Always verify you are using portal.polygon.technology to avoid phishing attacks.
Want to see a comparison with zkEVM? Read our Polygon zkEVM Bridge guide. Or learn more about PoS Bridge fees and gas costs.
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