Gas fees are the transaction costs you pay to use the Ethereum network. Every operation on Ethereum — sending ETH, swapping tokens, interacting with smart contracts — requires computational resources. Gas fees compensate validators for processing these transactions. Fees are measured in \'gwei\' (a tiny fraction of ETH) and vary based on network demand. During high activity, fees can spike significantly, making simple transactions expensive.
Since EIP-1559, Ethereum gas fees consist of a base fee (burned) and a priority fee (tip to validators). The base fee adjusts automatically based on network congestion. When blocks are more than 50% full, the base fee increases; when less than 50% full, it decreases. You can set a max fee and max priority fee to control your spending. Wallets like MetaMask estimate these values automatically, but understanding them helps you optimize costs.
Time your transactions: gas fees are typically lowest during weekends and early morning hours (UTC). Use Layer 2 solutions like Arbitrum, Optimism, or Base for DeFi activities — fees are 10-100x cheaper. Batch transactions when possible. Use gas tracking tools like Etherscan Gas Tracker to monitor current fees. Set appropriate gas limits — don\'t overpay. Consider using ChangeNow for swaps instead of on-chain DEXes, as ChangeNow handles gas fees internally.
Layer 2 solutions process transactions off the main Ethereum chain, dramatically reducing fees while maintaining security. Arbitrum and Optimism are optimistic rollups with large DeFi ecosystems. Base (by Coinbase) offers low fees and growing adoption. zkSync and StarkNet use zero-knowledge proofs for even better scalability. You can bridge ETH to Layer 2 networks, or use ChangeNow to swap directly to Layer 2 tokens.