Gas fees, explained
The short answer
Gas fees are what you pay to have a transaction processed. They rise when the network is busy because users compete for limited block space.
What “gas” means
On Ethereum and similar networks, every action (sending tokens, swapping on a decentralized exchangeDecentralized exchange A smart-contract-based marketplace where people trade tokens directly from their own wallets., minting an NFT) needs computation. Gas is the unit that measures that work. A simple transfer needs a little gas. A complex DeFi transaction needs much more.
Your fee = gas used × price per unit of gas.
Why fees change
Each block has limited space. When many people want in at once, they bid up the price per unit of gas. The same swap might cost a few cents at a quiet moment and many dollars during a frenzy.
On Ethereum, part of each fee (the “base fee”) is burned, and an optional tip goes to the validator to prioritise your transaction.
How to pay less
- Use a layer 2Layer 2 A network built on top of a blockchain that processes transactions more cheaply and settles back to it. network, where fees are usually a small fraction of mainnet’s.
- Transact when the network is quieter.
- Don’t set custom gas limits unless you know what you’re doing. A failed transaction still costs gas.
Failed transactions still cost money
If a transaction runs out of gas or its conditions aren’t met, the network still did the work, so you still pay. That surprises a lot of newcomers.
Last reviewed Oct 3, 2026. Educational content only, not financial advice.