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Arbitrum vs Optimism
ARB vs OP
Two of crypto’s most-discussed assets, side-by-side. Key differences, recent coverage from TheChainPost, and an FAQ for both — no investment advice, no price predictions.
Layer 2
Arbitrum (ARB)
Largest Ethereum L2 by TVL. Optimistic rollup, Stylus (Rust) support.
- Launched
- 2021
- Consensus
- Optimistic Rollup (Ethereum L2)
At a glance
| Arbitrum (ARB) | Optimism (OP) | |
|---|---|---|
| Launched | 2021 | 2021 |
| Consensus | Optimistic Rollup (Ethereum L2) | Optimistic Rollup (Ethereum L2) |
| Category | Layer 2 | Layer 2 |
Latest ARB + OP coverage
No recent ARB or OP stories yet — check back soon.
Arbitrum vs Optimism FAQ
- What is Arbitrum?
- Arbitrum is an optimistic rollup on Ethereum built by Offchain Labs. Mainnet launched August 2021 as Arbitrum One; a second chain — Arbitrum Nova — targets gaming/social with AnyTrust data availability. By early 2026 it is consistently the largest L2 by TVL, rivalled only by Base.
- What does "optimistic rollup" mean?
- Transactions posted to L1 are assumed valid by default. A 7-day challenge window lets any watcher submit a fraud proof to revert fraudulent batches. The sequencer (currently centralised, operated by Offchain Labs) orders transactions; decentralising it is on the roadmap. Security ultimately inherits from Ethereum.
- What is Optimism?
- Optimism is an optimistic rollup L2 on Ethereum, launched mainnet 2021 by OP Labs. The broader project is the Optimism Collective — a bicameral governance with the Token House (OP holders) and Citizens' House (soulbound voting for Retroactive Public Goods Funding).
- What is the OP Stack?
- Open-source codebase for launching optimistic rollups. Base (Coinbase), World Chain, Zora, Mode, and dozens of others are OP Stack chains. Together they form the "Superchain" — shared sequencing infrastructure, bridging, and a common governance layer. It is the dominant rollup framework by chain count.
- How do Arbitrum and Optimism compare?
- Arbitrum (ARB): Largest Ethereum L2 by TVL. Optimistic rollup, Stylus (Rust) support. Launched 2021, runs Optimistic Rollup (Ethereum L2). Optimism (OP): OP Stack Superchain (Base, World Chain, Zora). Retroactive Public Goods Funding. Launched 2021, runs Optimistic Rollup (Ethereum L2). These are two structurally different designs — read the news feed above for recent developments on each, and consult a qualified advisor before making any financial decision.
General information, not investment advice. Cryptocurrencies are volatile — do your own research and consult a qualified advisor before making decisions.