What is a gas fee?
DefinitionA gas fee is the network fee you pay to have a transaction processed on a blockchain such as Ethereum. It pays the network, not your wallet app, and it is always paid in the network’s own coin, such as ETH or BNB, even when you send a token.
How gas works
Gas measures the computing work a transaction needs. A simple coin transfer uses a little gas; a token transfer or a smart-contract call uses more. Your fee is the gas used multiplied by the price per unit of gas, and that price rises and falls with demand for block space.
Since the London upgrade of 2021, the gas price on Ethereum has two parts: a base fee set by the network, which is burned, and an optional priority fee, or tip, for the validator. When blocks are busy, the base fee climbs.
Which coin pays the fee
The fee is always paid in the native coin of the network you use. That is why you can hold USDT and still be unable to send it.
- Ethereum, Arbitrum, Optimism and Base: ETH
- BNB Smart Chain: BNB
- Polygon: POL
- Avalanche C-Chain: AVAX
- Tron: TRX, or energy and bandwidth
- TON: TON
Mistakes and surprises
A transaction that fails on an EVM network still costs gas, because the network did the work of running it. Setting a fee too low, on the other hand, can leave a transaction pending for a long time.
Keep a little of the gas coin on every network where you hold tokens. Sending your entire balance of ETH or BNB can leave the tokens that remain stuck until you top up again.
Gas fees in Waletifi
Waletifi shows the network fee, including its value in your own currency, on the review screen before you confirm. If you hold tokens but not the coin needed for gas on that network, the app warns you before you try to send.
