What Are Gas Fees?
Every time you do something on a blockchain (send crypto, swap tokens, load a card, buy a gift card), the network charges a small fee to process your transaction. This fee is commonly called a gas fee or network fee.
Think of it like postage on a letter. The blockchain network needs to verify and record your transaction, and gas is what pays for that work.
Why Do I Need a Specific Token for Gas?
Each blockchain has its own native token that's used to pay gas fees. You need a small amount of this token in your wallet before you can send, swap, or spend any other token on that chain.
Here are the native tokens for common chains:
Ethereum (ETH chain): ETH
BNB Smart Chain: BNB
Solana: SOL
Base: ETH
TRON: TRX (uses a bandwidth/energy system rather than traditional gas)
Bitcoin: BTC
Polygon: POL
For example, if you have USDT on the BNB Smart Chain and want to send it somewhere, you'll need a small amount of BNB in the same wallet to cover the gas fee.
How Much Are Gas Fees?
Gas fees vary by network and by how busy the network is at any given moment. Some chains are much cheaper than others:
Very low fees: Base, Solana, BNB Smart Chain, TRON (often fractions of a cent)
Moderate fees: Polygon
Higher fees: Ethereum, Bitcoin (can range from a few cents to several dollars depending on network congestion)
Zypto always shows you the estimated gas fee before you confirm a transaction, so you'll know the cost upfront.
What If I Don't Have Enough for Gas?
If you see a message about insufficient funds for gas or network fees, it means your wallet doesn't have enough of the chain's native token to process the transaction. Here's what you can do:
Option 1: Buy the native token
Use the "Buy Crypto" feature in Zypto to purchase a small amount of the native token you need (ETH, BNB, SOL, etc.) directly into your wallet.
Option 2: Use a cross-chain swap
If you have crypto on another chain, you can swap it to the native token you need using one of Zypto's integrated swap providers (ChangeNow, LetsExchange, or SwapKit). For example, if you have USDT on Ethereum but need BNB for a transaction on BNB Smart Chain, you can swap USDT (ETH) to BNB (BSC) directly in the app.
Option 3: Send native tokens from another wallet
If you have the native token in an external wallet (like an exchange), you can send a small amount to your Zypto wallet address on the correct chain.
Tips for Managing Gas Fees
Keep a small buffer: Always keep a small amount of native tokens (ETH, BNB, SOL, etc.) in your wallets so you're never stuck.
Choose low-fee chains when possible: If you're sending stablecoins like USDC, using Base or BNB Smart Chain will cost far less in gas than Ethereum.
Check before large transactions: Gas fees on Ethereum and Bitcoin can spike during busy periods. If speed isn't critical, waiting a few hours can sometimes save you money.
TRON works differently: TRON uses a bandwidth and energy system. You may need to "freeze" TRX to get bandwidth for free transactions, or pay a small TRX fee. The app handles most of this automatically.
Common Error Messages
"Not enough gas" or "Insufficient funds for gas"
You need more of the chain's native token. See the options above.
"Not enough SOL to cover fees"
You need a small amount of SOL in your Solana wallet. Even if you have other tokens on Solana, you still need SOL specifically to pay for transactions.
Gas fee showing as $0.00 or <$0.01
On low-fee chains like Base, Solana, or BNB Smart Chain, gas fees can be a tiny fraction of a cent. If you see $0.00 or <$0.01, this means the fee is under one cent, not that it's free. You will still need a small amount of the chain's native token in your wallet to complete the transaction.
If you're still stuck, our support team is happy to help you work out the best way to get the gas you need for your transaction.