Rollup
Also known as: Layer 2 Rollup, L2 Rollup
A Layer 2 scaling solution that executes transactions off-chain and posts compressed data to the main blockchain for security.
Rollups are Layer 2 scaling solutions that execute transactions off the main blockchain (Layer 1) while still inheriting its security. They "roll up" hundreds or thousands of transactions into a single batch, posting compressed data back to the L1 for verification.
How Rollups Work:
- Users submit transactions to rollup sequencer
- Sequencer executes transactions off-chain
- Batched transaction data compressed and posted to L1
- L1 provides data availability and finality
- Security derived from underlying L1 (usually Ethereum)
Two Main Types:
Optimistic Rollups: - Assume transactions are valid by default - Fraud proofs can challenge invalid batches - 7-day challenge period for withdrawals - Examples: Arbitrum, Optimism, Base
ZK (Zero-Knowledge) Rollups: - Validity proofs mathematically verify correctness - No challenge period needed - Faster finality but more complex - Examples: zkSync, StarkNet, Scroll, Linea
Comparison:
| Feature | Optimistic | ZK |
|---|---|---|
| Withdrawal time | ~7 days | Minutes |
| Proof cost | Lower | Higher |
| EVM compatibility | Easier | Harder |
| Maturity | More mature | Rapidly evolving |
Benefits: - 10-100x lower gas costs vs L1 - Inherit Ethereum security - Higher throughput - Same developer tools (EVM compatible)
Rollup Ecosystem (2026): Rollups have become the dominant scaling approach, with Arbitrum and Base leading in TVL, and ZK rollups rapidly gaining ground as technology matures.
Related Crypto Analysis
Explore how Rollup applies to these cryptocurrencies with in-depth STRICT score analysis.