DeFi Education5 min read
Gas Fees Explained: Why Blockchain Transactions Cost Money
Learn what gas fees are, why they vary so much, and how to minimize transaction costs across different blockchains.
What Are Gas Fees?
Gas fees are the transaction costs paid to blockchain validators for processing and confirming your transactions. On Ethereum, gas is measured in gwei (billionths of ETH), and the total cost depends on the transaction's computational complexity and current network demand.
Why Do Gas Fees Vary?
Gas prices fluctuate based on network congestion. When many users submit transactions simultaneously, they compete for limited block space by offering higher gas prices. During NFT mints or market volatility, Ethereum gas can spike to hundreds of dollars per transaction.
Gas on Different Networks
- Ethereum L1: $1-50+ depending on congestion
- Arbitrum: $0.01-0.50, uses L1 for security
- Base: $0.01-0.10, Coinbase's L2
- Optimism: $0.01-0.30, optimistic rollup
- Polygon: $0.001-0.05, sidechain
- Solana: $0.001-0.01, high throughput
Tips to Save on Gas
- Use Layer 2 networks: Same security, fraction of the cost
- Time your transactions: Gas is cheapest during off-peak hours
- Batch transactions: Some protocols support batched operations
- Use multi-chain platforms: Alkizen routes your trades across 75+ chains, automatically finding the most cost-effective execution path.