Why are crypto gas fees so high sometimes?

Key takeaways

• Gas fees pay for limited block space and computation.
• Ethereum fees have a burned base fee plus an optional tip.
• Fees spike when many users transact at the same time.
• Layer 2 networks became much cheaper after the 2024 Dencun upgrade.
• Timing and network choice are the easiest ways to pay less.

Every transaction on a blockchain such as Ethereum costs a fee. On Ethereum and similar networks this is called a gas fee. Fees can be a few cents one day and many dollars the next. The reason is simple: block space is limited, and users compete for it.

What “gas” means

Gas is a unit that measures how much computation a transaction needs. A simple transfer uses less gas than a complex DeFi trade or an NFT mint. The fee you pay is:

gas used × price per unit of gas

The price per unit is usually quoted in gwei, a tiny fraction of ETH (1 gwei = 0.000000001 ETH). See wei and gwei.

How Ethereum fees work since EIP-1559

Since the London upgrade in August 2021, an Ethereum fee has two parts:

• Base fee: set by the protocol for each block. If the previous block was more than half full, the base fee rises; if it was less full, it falls. The base fee is burned, which removes ETH from circulation.
• Priority fee (tip): an optional extra paid to the validator to include your transaction faster.

Your wallet sets a maximum fee you are willing to pay. You pay the base fee plus your tip, up to that maximum.

Why fees spike

1. Demand surges. Popular token launches, NFT mints, airdrop claims or market crashes cause many people to transact at once.
2. Complex transactions. Swaps, bridging and contract interactions need more gas than simple transfers.
3. Limited block space. Each block has a gas limit, so when demand exceeds it, the base fee keeps rising block by block.
4. Price of the coin. Fees paid in ETH become more expensive in euro or dollar terms when ETH’s price rises.

Why some networks are cheaper

Networks have different designs and trade-offs. Solana is built for high throughput with low fees. Ethereum layer 2 networks (rollups) bundle many transactions and post them to Ethereum, which spreads the cost. Since the Dencun upgrade in March 2024 (EIP-4844), rollups can post data more cheaply, and many layer 2 fees fell sharply. Compare chains on our ETH vs SOL page.

How to pay less in fees

• Transact at quieter times. Fees often drop when activity in the US and Europe is low, such as weekends or nights in those regions. Check a gas tracker first.
• Use a layer 2 network for frequent small transactions.
• Do not set the tip too high unless speed really matters.
• Batch actions where possible instead of many small transactions.
• Avoid failed transactions. A failed transaction can still cost gas. Check slippage and approvals before sending. See slippage.

Bitcoin fees work differently

Bitcoin does not use gas. Fees depend on the transaction’s size in virtual bytes and on demand for block space, measured in satoshis per vbyte. The idea is the same: when blocks are full, users who pay more get included first.

Common mistakes to avoid

• Setting a very high priority fee out of impatience.
• Sending complex transactions without checking slippage, causing failures.
• Moving small amounts on mainnet when a layer 2 would do.
• Forgetting that fees in euros rise when the coin’s price rises.

Bottom line

Gas fees are high when many people want limited block space at the same time. Ethereum’s base fee adjusts automatically and is burned, while tips speed up inclusion. Choosing quieter times and layer 2 networks are the easiest ways to pay less. Check the live price of Ethereum to see what a fee costs in your currency.

Frequently asked questions

Who receives Ethereum gas fees?

The base fee is burned. The priority fee (tip) goes to the validator who includes the transaction.

Why did my failed transaction still cost a fee?

The network did computation work trying to execute it, so the gas used up to the failure point is still paid.

What is gwei?

A small unit of ETH: one gwei is one billionth of an ETH. Gas prices are usually quoted in gwei.

Are layer 2 fees always lower?

Usually much lower than Ethereum mainnet, especially since the 2024 Dencun upgrade, but they can rise during heavy demand.

Why do NFT mints cause fee spikes?

Many users try to transact in the same few blocks, bidding up the base fee and tips.

Do I need ETH to pay fees on a layer 2?

On many Ethereum layer 2 networks fees are paid in ETH, but some use other tokens. Check the network’s documentation.

Sources

• Ethereum.org: Gas and fees
• EIP-1559: Fee market change
• EIP-4844: Shard blob transactions (Dencun)
• Ethereum.org: Layer 2

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