A gas fee is the cost you pay to make something happen on a blockchain. It’s like paying postage to send a letter (except instead of envelopes, you’re sending digital transactions or running smart contracts). Or think of gas fees like gasoline for your car. You need gasoline to move your car (unless it's an electric car, but you get the point). On a blockchain, gas is what powers every action, from sending crypto to running smart contracts. No gas, no transaction.
Simple transaction? Small fee (usually). Think of sending someone $10 worth of crypto. That’s a straightforward action:
You sign it.
The network checks your balance.
It updates the ledger.
That’s a light lift for the blockchain, so the gas fee is usually low—just enough to cover the network’s effort to process and confirm it.
Complex smart contract? Bigger fee (usually).
Now imagine you’re using a decentralized app (dApp) to:
Swap tokens on a decentralized exchange
Mint an NFT
Trigger an insurance payout
Submit a vote in a DAO
Run a multi-step financial transaction
Each of those tasks involves many steps under the hood (checking conditions, pulling data, updating multiple records). That’s a lot more work for the network, and it gets priced in through higher gas fees. In general, the more work your transaction asks the network to do, the more gas it needs.
Think of it like this: sending one email is easy. But running a full database query, uploading files, and syncing with three systems will likely take more server power and more cost.
Something to keep in mind is that gas fees are always paid in the blockchain’s native coin.
Avalanche → AVAX
Ethereum → ETH
Bitcoin → BTC
BNB Chain → BNB
Blockchains charge based on computation, not just “how much money” is being moved. That’s why $1,000 sent in crypto might cost less gas than minting one NFT. This matters because if gas fees are too high, certain use cases become unrealistic. Gas fees are more than just technical costs. They directly impact accessibility and fairness.