Why Ethereum Transactions Got Cheap: Layer 2 Rollups in Plain Words
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5 min read
You swap a small amount of crypto and the fee is a few cents. Last time you used Ethereum itself, it may have cost several dollars. Same coin, same wallet. What changed? Most likely you used a layer 2, and that is what this post explains.
A layer 2 (L2) is a separate network that sits on top of Ethereum and does the busy work for it. The most common type is called a rollup. Rollups are the main reason Ethereum layer 2 fees fell so far.
Facts below come from web search summaries read on 11 October 2026. We could not open L2BEAT's own dashboard from our research environment, so check it directly for live numbers.
Think of Ethereum as one busy toll road. Every car (transaction) must be checked by every toll booth (computer) on the network. That keeps it safe. It also means the road is slow and the toll gets high when it is crowded. We covered how that fee works in our gas fees post.
A rollup is like a bus. Hundreds of passengers ride together. The bus pays the toll once. Each passenger pays only a small share.
A rollup does three simple things:
Ethereum does not redo every transaction. It stores the package and, depending on the design, checks it. Your funds are still protected by Ethereum's security, at least in theory. That is the big promise of a rollup.
Rollups were already cheaper, but one upgrade made them much cheaper. In March 2024 Ethereum shipped an upgrade called Dencun, which included a change known as EIP-4844. It added a new, cheaper lane on Ethereum called a blob. Rollups now post their packages as blobs instead of in the costly regular lane.
Search summaries of several explainers say layer 2 fees fell by about 90 to 95 percent after it. The drop was not equal everywhere. One comparison table cited roughly 98 percent for Base and Optimism, about 90 percent for Arbitrum and about 65 percent for zkSync Era. We could not trace that table to a primary dataset, so treat the per-chain numbers as rough.
There are two main kinds. They differ in how the network proves it did the math right.
Optimistic rollups assume the bundle is honest unless someone proves otherwise. There is a waiting period, usually 7 days, in which anyone can challenge it. Arbitrum, OP Mainnet and Base are optimistic. Moving money back to Ethereum through their official bridge takes about 7 days.
ZK rollups (zero-knowledge) attach a mathematical proof to each bundle. Ethereum checks the proof right away, so no long wait is needed. Sources disagree on exact exit times, from a few hours to about a day. ZKsync Era is an example.
| Optimistic | ZK | |
|---|---|---|
| How it proves honesty | Challenge window | Math proof up front |
| Official exit to Ethereum | About 7 days | Hours to about a day |
| Examples | Base, Arbitrum One, OP Mainnet | ZKsync Era |
In practice many people exit faster through third-party bridges. That adds a different risk, covered below.
L2BEAT is a site that tracks layer 2 networks and rates their safety. Search summaries of its data put total value secured on layer 2s at roughly $42 to $44 billion in late September and early October 2026. Sources vary on the exact total because of dates and methods.
In the 28 September 2026 snapshot, Base held about $16.1 billion, Arbitrum One about $11.5 billion and OP Mainnet about $1.9 billion. The same summary labelled all three as Stage 1. These are third-party figures, not NetWort data.
Cheap does not mean risk free. Three things to understand.
Sequencers. A sequencer is the computer that decides the order of transactions on a rollup. According to L2BEAT's risk analysis as summarised in search results, Arbitrum's is run by Offchain Labs, Base's by Coinbase and OP Mainnet's by the Optimism Foundation. One company ordering transactions is a single point of failure. The same sources say major rollups let you send a transaction straight to Ethereum if the sequencer misbehaves, so you can still exit.
Stages. L2BEAT grades rollups from Stage 0 to Stage 2. Stage 1 means a working fraud-proof system exists but the builders keep some control. Stage 2 means the rollup runs mostly without trusted operators. The three biggest were Stage 1 in the summaries we read. None was Stage 2.
Bridges. Moving money between Ethereum and a layer 2 uses a bridge, and bridges are a favourite target for hackers. Read how bridge hacks and wrapped tokens work before moving real money.
Cheaper layer 2 use can mean fewer fees paid to Ethereum itself. How that affects ETH supply is a separate question, which we cover in Ethereum issuance and burn. We make no prediction about price.
Fees on layer 2 are only half of the story for your portfolio. The other half is how ETH itself behaves. Open the ETH page on NetWort and look at its price history and volatility, so you know how much the asset moves before you pay any fee to use it.