When a popular base layer like Ethereum becomes congested, fees climb and confirmations slow. Layer 2 networks are the main remedy. They move the bulk of activity off the base chain, batch many transactions together, and periodically post a compressed summary back down to the layer 1. Users enjoy far lower fees and quicker confirmations, yet the arrangement still inherits the underlying security of the base chain, because that is where final settlement ultimately happens.
Rollups are the leading approach. They bundle hundreds or thousands of transactions into one, execute them away from the base layer, and submit proof of the outcome back to it. Well-known Ethereum layer 2s include Arbitrum, Optimism and various zk-rollups. The benefit is easy to feel in practice: a swap that might cost several pounds in fees on Ethereum's base layer can cost a small fraction of that on a layer 2, which is a large part of why they have grown so quickly.
Layer 2s are central to how crypto scales without abandoning decentralisation, but they add moving parts of their own, including bridges to shuttle funds between layers and varying degrees of maturity and trust assumptions. Crucially, they lower cost rather than eliminate risk, so it pays to understand the specific network you are using rather than treating all layer 2s as identical.
Key takeaways
- A layer 2 processes transactions off a base chain to cut fees and lift speed, then settles back to the layer 1.
- Rollups, which batch many transactions into one, are the dominant layer 2 design on Ethereum.
- Layer 2s inherit the base chain's security but add extra components like bridges and their own trust assumptions.
Layer 2 — preguntas frecuentes
Why are transactions cheaper on a layer 2?
Because they are processed off the congested base chain, with only a compressed summary posted back to it. Spreading the base layer's cost across many bundled transactions dramatically lowers the fee each individual user ends up paying.
Is a layer 2 as safe as the layer 1 beneath it?
Layer 2s aim to inherit the base chain's security, but they add extra components and trust assumptions, and their maturity varies. They reduce cost rather than remove risk, so it is worth understanding the particular network you choose to use.
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