Layer 1 vs Layer 2
Improvements in blockchain technology, especially around layer 2 solutions, have fundamentally changed how users interact with Ethereum, Bitcoin, and other layer 1 networks. The core innovation of layer 2 protocols is moving most transaction activity off the main chain, while still relying on layer 1 for security and final settlement. For users deciding whether to migrate funds to a layer 2 network, understanding how this works is key.
Layer 2 solutions address the scaling challenges of layer 1 networks by batching transactions off-chain and posting only the compressed data back to the base chain. In systems like Ethereum’s optimistic and zero-knowledge rollups, transactions are batch-transposed onto the main Ethereum chain. This shifts the burden of processing and most of the fee pressure off the base Ethereum layer while still relying on it for security and data anchoring.
Perhaps the most significant benefit of layer 2 rollups is the reduction in transaction fees. By batching transactions and sharing the fixed costs of posting data back to the mainnet across many users, rollups significantly reduce the per-user cost. To illustrate, in scenarios laid out by Ethereum, gas costs are noticeably lower on layer 2 rollups than on the main Ethereum network.
However, the user experience still has limitations and waiting periods. With optimistic rollups, transaction batches are finalized on-chain, but there is a roughly 7-day withdrawal period before assets can be moved back to the main Ethereum network. In practice, this can be bypassed by using a liquidity provider that makes payouts to the user before the period expires. Zero-knowledge (zk) rollups, on the other hand, offer a more streamlined withdrawal process that has no challenge period, thus providing same-day transfers.
Though similar in their off-chain transaction handling, zk-rollups and the Bitcoin Lightning Network diverge significantly in design and application. Ethereum’s rollups ultimately aim to enable a broader smart contract and trustless settlement system than pure payments. The Bitcoin Lightning Network, conversely, is intended for fast, scalable, off-chain payments conducted via payment channels and can handle state changes within a script, but does not provide the same broad smart contract capability.
For users assessing their options, moving assets to a layer 2 platform will require navigating bridges that allow cross-layer transactions. Unlike rollups themselves, bridges come with risks — the security of an asset transfer is tied to the smart contracts and network protocols being used. Users must evaluate whether the speed and cost benefits of layer 2 are worth the exposure to the risks introduced by bridges.
When deciding between staying on layer 1 or moving to a faster, cheaper layer 2 option, the answer comes down to each user's needs. By offloading transaction workload to layer 2, users can expect lower costs and faster transaction finality. For some protocols, the tradeoff is a challenge period for cross-transfers. However, taking full advantage of these benefits means accepting the additional risks and considerations that come with using layer 2 networks and bridges.
General information, not financial, investment or tax advice. Rules, fees and allowances change: check the figure with HMRC, the FCA or the service itself before you act.
