Bridging ERC-20 tokens to other blockchains allows them to be used on different networks (e.g., Binance Smart Chain, Polygon, Avalanche, etc.). This process typically involves locking or burning tokens on Ethereum and minting wrapped or pegged versions on the destination chain. Here’s how it works:
How Token Bridging Works
Lock & Mint: The original ERC-20 tokens are locked in a smart contract on Ethereum, and a wrapped version is minted on the destination chain.
Burn & Unlock: When bridging back, the wrapped tokens are burned, and the original tokens are unlocked on Ethereum.
Liquidity Pools: Some bridges use liquidity pools on both chains instead of locking.
Methods to Bridge ERC-20 Tokens
Official Bridges (Recommended)
Many projects provide their own bridges (e.g., Polygon PoS Bridge, Arbitrum Bridge).
Example: USDC, USDT, and DAI often have official bridges.
Third-Party Bridges
Multichain (formerly Anyswap) – Supports many chains.
cBridge (by Celer) – Fast and low-cost bridging.
Synapse Protocol – Cross-chain swaps with liquidity pools.
Wormhole – Supports Ethereum, Solana, BSC, etc.
Decentralized Exchanges (DEXs) with Cross-Chain Support
Thorchain – Native cross-chain swaps.
Orbiter Finance – Low-fee Ethereum L2 bridging.
Wrapped Tokens (Manual Bridging)
Example: Wrap ETH as WETH, then bridge to WBTC on another chain.
Step-by-Step Bridging Process (Using a Bridge)
Choose a Bridge (e.g., Multichain, cBridge).
Connect Your Wallet (MetaMask, WalletConnect, etc.).
Select Tokens & Chains
Source Chain: Ethereum
Destination Chain: e.g., BSC, Polygon
Token & Amount
Approve & Confirm
Approve the bridge contract to spend your tokens.
Pay gas fees (Ethereum fees can be high).
Receive Bridged Tokens
Tokens may appear as "pegged" or "wrapped" (e.g.,
USDC.eon Avalanche).
Popular ERC-20 Bridges
| Bridge | Supported Chains | Fees | Speed |
|---|---|---|---|
| Multichain | Ethereum, BSC, Polygon, Avalanche, Fantom | Variable | Medium |
| cBridge | Ethereum, Arbitrum, Optimism, Polygon | Low | Fast |
| Synapse | Ethereum, Avalanche, BSC, Arbitrum | Medium | Fast |
| Polygon Bridge | Ethereum ↔ Polygon | Low | ~10-30 mins |
Risks & Considerations
Smart Contract Risk: Use well-audited bridges.
Centralization Risk: Some bridges rely on validators.
Liquidity Issues: Check if the destination chain has enough liquidity.
Different Token Standards: Some chains use different formats (e.g., BEP-20 on BSC).
Alternatives to Bridging
Cross-Chain Swaps (e.g., Thorchain, Rango Exchange) allow direct swaps without bridging.
CEX Transfers: Some exchanges (Binance, Kraken) support multi-chain deposits.
Best Choice?
For Ethereum ↔ Polygon/Arbitrum/Optimism: Use the official bridge.
For Ethereum ↔ BSC/Avalanche: Use Binance Bridge or Multichain.
For Multi-Chain Support: Wormhole or LayerZero.
