What are crypto bridges?

Blockchains do not talk to each other by default. Ethereum does not know what you hold on Arbitrum. Bitcoin does not see your Solana wallet. A bridge is the plumbing that moves value between those separate ledgers.

Most bridges follow one of these patterns:

Model	How it works	Example use
Lock & mint	Lock tokens on chain A; mint a wrapped copy on chain B	ETH → bridged ETH on an L2
Burn & unlock	Burn wrapped tokens on B; release originals on A	Withdrawing from L2 to mainnet
Liquidity network	Swap into a pool on A; receive equivalent from a pool on B	Fast third-party bridges
Custodial	A company holds funds and credits you elsewhere	Some CEX withdrawals to L2

You are rarely moving the same coin atomically across chains. You are usually trading custody of one representation for another — with a bridge contract or operator in the middle.

Crypto split into many networks, each with different fees, speed, and apps:

• Ethereum mainnet — high security, high fees
• L2s (Arbitrum, Base, Optimism) — cheaper transactions, still tied to Ethereum
• Alt L1s (Solana, Avalanche) — different ecosystems entirely
• App-chains (HyperEVM, dYdX chain) — optimised for one platform

You buy ETH on mainnet but want to use a cheap DeFi app on Base. You hold USDC on Ethereum but need it on Polygon. A bridge is how you get funds where the app lives.

After bridging, you often hold a wrapped version — not the “original” native asset on that chain:

• WETH — wrapped ETH for DeFi contracts
• Bridged USDC — USDC that entered via a specific bridge (contract address matters)
• WHYPE on HyperEVM — wrapped HYPE for EVM apps

Same ticker symbol on a block explorer does not mean same token. Always check the contract address and which bridge issued it. Two different “USDC” tokens can exist on one chain from different bridges.

Some moves feel like bridging but stay inside one platform:

• Hyperliquid Core ↔ HyperEVM — same account, shared state; you shift HYPE between trading and app sides without a third-party bridge
• CEX internal transfers — the exchange moves database entries, not on-chain bridge logic (until you withdraw)

Confusing an in-platform transfer with a cross-chain bridge is how people underestimate risk — or overestimate it.

• Smart contract exploits — bridge contracts hold huge TVL; hacks have drained billions historically
• Fake bridge sites — phishing UIs that steal approvals or deposits
• Wrong network sends — sending mainnet ETH to an L2 address without bridging (or vice versa) can mean lost or stuck funds
• Delayed withdrawals — official L2 bridges can take days during congestion; liquidity bridges can fail if pools are empty
• Wrapped token depeg — bridged asset may not redeem 1:1 if the bridge or issuer fails

1. Use official bridges when available (e.g. from the L2’s own site, linked from the project’s docs).
2. Start with a small test amount before moving size.
3. Verify the URL — bookmark official bridge pages; don’t click ads or DMs.
4. Check your wallet network before and after — source chain to deposit, destination chain to receive.
5. Read the recipient token contract on the destination explorer if you’re bridging stablecoins or high-value assets.
6. Budget time — official bridges can be slow; “instant” often means more counterparty risk.

See also: crypto networks for how L1s and L2s relate, and Hyperliquid for when a transfer is not a bridge.