What is Gas?
Gas is the unit of measurement for the computational work required to execute a transaction on the Ethereum network (and other EVM blockchains). Think of it like fuel for your car -- every action on the blockchain requires some gas to execute.
Why Does Gas Exist?
Gas serves two important purposes:
- Prevents spam: If transactions were free, attackers could flood the network with millions of useless transactions. Gas fees make this economically impractical.
- Compensates validators: Validators (or miners) spend real resources (electricity, hardware) to process transactions. Gas fees are their payment for this work.
How Gas Prices Work
Gas pricing has two components:
- Gas Limit: The maximum amount of gas you're willing to use for a transaction. A simple ETH transfer uses about 21,000 gas. A complex smart contract interaction might use hundreds of thousands.
- Gas Price (in Gwei): How much you're willing to pay per unit of gas. 1 Gwei = 0.000000001 ETH.
Transaction Fee = Gas Used x Gas Price
For example: 21,000 gas x 20 Gwei = 420,000 Gwei = 0.00042 ETH
EIP-1559: How Modern Gas Works
Since the London upgrade, Ethereum uses a two-part fee system:
- Base Fee: Set by the protocol based on network demand. This part is burned (destroyed), reducing the total supply of ETH.
- Priority Fee (Tip): An optional extra payment that goes directly to the validator. Higher tips get your transaction processed faster.
Tips for Saving on Gas
- Check gas prices first: Use Omniscanner's Gas Tracker to see current gas prices before transacting.
- Time your transactions: Gas prices are typically lowest during off-peak hours (weekends, early morning UTC).
- Use Layer 2 networks: Chains like Base, Arbitrum, and Optimism offer the same EVM functionality at a fraction of the gas cost.
- Batch transactions: Some protocols let you batch multiple operations into a single transaction.
Check Current Gas Prices
Visit the Omniscanner Gas Tracker to see real-time gas prices across multiple EVM chains.