Ethereum Bridge: How Cross-Chain Transfers Work and Which Ones Are Safe

When you move ETH from Ethereum to Polygon or Solana, you’re using an Ethereum bridge, a protocol that locks tokens on one blockchain and mints equivalent tokens on another, enabling cross-chain transfers without centralized intermediaries. Also known as a cross-chain bridge, it’s what lets you use DeFi apps on cheaper networks while still holding Ethereum-based assets. Without these bridges, you’d be stuck on Ethereum—paying high gas fees just to swap tokens or join a yield farm on a different chain.

But not all bridges are built the same. Some, like cBridge, a multi-chain bridge developed by Celer Network that supports over 30 blockchains and has processed billions in transfers with strong audit history, are trusted by millions. Others, like the fake Purple Bridge, a non-existent platform that scammers use to trick users into sending funds with promises of free tokens, are outright frauds. The difference? Real bridges have public audits, transparent code, and active user bases. Fake ones vanish after a few million in deposits.

Most Ethereum bridges work by locking your tokens in a smart contract and issuing wrapped versions on the target chain. For example, if you send 10 ETH to an Ethereum-Polygon bridge, you get 10 wETH (wrapped ETH) on Polygon. When you want your ETH back, you burn the wETH and the original ETH is released. Simple in theory—but if the bridge’s smart contract is hacked or the operators run off, your funds are gone. That’s why you should only use bridges backed by major projects like Avalanche Bridge, Arbitrum Bridge, or the official Optimism Gateway.

And it’s not just about security. A good bridge should be fast, cheap, and support the tokens you actually use. Some bridges only work with ETH or stablecoins. Others let you move NFTs or governance tokens too. If you’re jumping between DeFi apps on different chains, you need a bridge that handles your whole portfolio—not just one token.

What you’ll find below are real reviews of bridges, airdrops tied to bridge usage, and warnings about fake platforms pretending to be bridges. You’ll see how users got burned by fake Ethereum bridges like Purple Bridge, how some DeFi rewards depend on bridge activity, and why a bridge with zero volume is a red flag. No fluff. No hype. Just what works, what doesn’t, and how to protect your money when moving between blockchains.