Layer 2
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In Brief
A Layer 2 (L2) is a secondary network built on top of a base blockchain (Layer 1) that processes transactions off the main chain to make them faster and cheaper, while inheriting the security of the underlying Layer 1.
What Is a Layer 2?
A Layer 2 (L2) is a secondary protocol built on top of an existing blockchain — the Layer 1 (L1) — designed to make transactions faster and cheaper. Instead of processing every transaction directly on the main chain, a Layer 2 handles them off-chain or in batches, then settles the results back to the Layer 1, inheriting its security.
Layer 2 solutions exist to solve the scalability problem: base chains like Ethereum can become slow and expensive when demand is high. L2s like Arbitrum, Optimism, Base, and Polygon dramatically increase throughput while keeping fees low.
Why Are Layer 2s Needed?
Base blockchains face the blockchain trilemma — the difficulty of achieving security, decentralization, and scalability all at once. When a Layer 1 prioritizes security and decentralization, throughput suffers, leading to congestion and high fees. Layer 2s add scalability on top without compromising the L1's security.
How Does a Layer 2 Work?
Transactions are executed on the Layer 2 network rather than directly on the Layer 1.
The L2 bundles or compresses many transactions together.
A summary (and proof) of these transactions is periodically posted to the Layer 1.
The Layer 1 provides the final security and settlement guarantees.
Users get faster, cheaper transactions while ultimately relying on L1 security.
Types of Layer 2 Solutions
| Type | How It Works | Examples |
|---|---|---|
| Optimistic Rollups | Assume transactions are valid; allow challenges | Arbitrum, Optimism, Base |
| ZK-Rollups | Use cryptographic proofs to verify transactions | zkSync, Starknet, Polygon zkEVM |
| State Channels | Off-chain transactions settled on-chain later | Lightning Network (Bitcoin) |
| Sidechains | Independent chains linked to the L1 | (varies; security differs) |
Layer 1 vs Layer 2
| Feature | Layer 1 | Layer 2 |
|---|---|---|
| Role | Base settlement layer | Scaling layer on top |
| Speed | Slower | Faster |
| Fees | Higher | Lower |
| Security source | Itself | Inherited from L1 |
| Examples | Ethereum, Bitcoin | Arbitrum, Optimism, Base |
Layer 2s and Trust Wallet
Trust Wallet supports a wide range of Layer 2 networks alongside their Layer 1 base chains, so you can transact with lower fees and faster confirmations. As a multi-chain, non-custodial wallet covering 100+ blockchains, Trust Wallet lets you hold, send, swap, and bridge assets across L1s and L2s — all while keeping full control of your private keys.