Gas Fees
In plain English
The price you pay for computation on a blockchain. Gas measures how much work your transaction takes; the fee is that work multiplied by the current price per unit.
What are gas fees?
Gas is the unit that measures computational work on Ethereum and similar networks. Every operation — a simple transfer, a token swap, minting an NFT — costs a set amount of gas. Your fee is that gas amount multiplied by the price you are willing to pay per unit.
Why the concept exists
Blockchains are shared computers with limited capacity. Charging per unit of computation does two things: it stops anyone from clogging the network with endless free operations, and it pays the validators who process and secure transactions.
A plain ETH transfer costs 21,000 gas. A token swap on a decentralised exchange might cost ten times that, because the smart contract does far more work.
How the price is set
On Ethereum, each block has a base fee that adjusts automatically: it rises when blocks are full and falls when they are not. On top of that you can add a priority fee — a tip that encourages validators to include your transaction sooner. The base fee is burned, permanently removing that ETH from supply; the tip goes to the validator.
This means your final cost depends on network demand at that moment, not on how much money you are sending. Moving $10 and moving $10 million can cost exactly the same.
How to pay less
Timing matters most: fees typically fall during quieter hours. Wallets let you set a lower priority fee if you are not in a hurry. Layer 2 networks such as rollups bundle many transactions together and settle them on the main chain in batches, which cuts the cost per transaction dramatically — often to a few cents.