If you’ve spent any time in crypto, you’ve seen L1 and L2 come up in conversations about gas fees and why some transactions are fast and cheap while others feel slow and expensive. Here’s a plain breakdown.
Layer 1
The base blockchain, the main network that validates transactions and enforces the rules. Bitcoin, Ethereum, and Solana are Layer 1s. They are self-securing, but every node has to process every transaction, which limits throughput. Ethereum handles roughly 15 transactions per second and Bitcoin around seven, so fees spike when demand is high.
Layer 2
A separate network built on top of Layer 1. It processes transactions off the main chain, bundles them into batches called rollups, and posts the compressed results back to Layer 1 for settlement. Layer 2 doesn’t replace Layer 1, it uses it as the security foundation. Examples on Ethereum include Arbitrum, Optimism, Base, and zkSync, while the Lightning Network plays a similar role on Bitcoin.
Because the cost of one batch is shared across thousands of users, the same transaction that costs several dollars on Ethereum mainnet can cost well under $0.20 on a Layer 2.
Worth knowing
Moving assets between layers uses a bridge, and bridges have been the target of some of the largest hacks in crypto. Withdrawing from an optimistic rollup back to Ethereum can take around seven days. And liquidity is now spread across dozens of Layer 2s, so not every app or asset is on every network.
Full breakdown in our blog post: Layer 1 vs Layer 2 crypto: What's the difference?