Fastest L2 block time, live across Robinhood, Arbitrum, Base and 7 more
BlockchainsArbitrum
Leads334 ms
- p99
- 500 ms
- rank
- #2
- samples
- 340,573
Optimism
Trails1.96 s
- p99
- 2.98 s
- rank
- #5
- samples
- 42,995
Arbitrum vs Optimism
Arbitrum leads on 5 of 6 shared benchmarks, Optimism on 1. Arbitrum wins on Fastest L2 block time, live across Robinhood, Arbitrum, Base and 7 more (334 ms vs 1.96 s), Fastest free public RPC for Ethereum, BNB, Polygon and 23 more chains (260 ms vs 331 ms), Fastest Wormhole VAA finalization by source chain, live latency (16.6 min vs 20.0 min), Fastest LayerZero source chain by end-to-end message delivery (27.76 s vs 1.2 min). Optimism wins on Fastest Chainlink CCIP source chain by end-to-end delivery latency (17.5 min vs 17.5 min).
Arbitrum
Optimistic rollup built on Nitro stack with a fast-finality sequencer. Sub-second block times (~250 ms) via a 250 ms default block interval, far below the 2 s OP Stack convention. 7-day fraud-proof window for L1 finality.
Optimism
Optimistic rollup and the canonical OP Stack reference implementation. 2-second sequencer block time, 7-day fraud-proof window, anchored to Ethereum L1 via batch submissions to the Optimism Portal.
Side by side measurements
Fastest free public RPC for Ethereum, BNB, Polygon and 23 more chains (plus Solana and Polkadot)
RPCsArbitrum
Leads260 ms
- p99
- 1.16 s
- rank
- #7
- samples
- 4,329
Optimism
Trails331 ms
- p99
- 436 ms
- rank
- #10
- samples
- 4,329
Latency is conditional on success: the harness times only calls returning a valid fresh block, so a mostly-failing endpoint can post a fast p50. Rows below 50 percent success are degraded; unresponsive probes pin below the table. The All chains aggregate favours single-chain foundation endpoints (Base, Binance, Arbitrum, Optimism, Avalanche officials) since they rank on one chain only; use a chain tab for honest comparison. Dead endpoints (cloudflare-eth POST returns -32603) are excluded.
Most reliable free public RPC, correctness incidents across 7 EVM chains
RPCsArbitrum
No data in window
Optimism
No data in window
A zero row means no incident was caught in the window, not a proof of correctness. Most providers post zero most days; this bench exists for the days they do not, and for the errors: a blocked eth_getLogs or a balance read gated behind a paid key at 40 blocks of depth counts as an incident because it is one from the caller's seat.
Fastest Wormhole VAA finalization by source chain, live latency
BridgesArbitrum
Leads16.6 min
- rank
- #10
- samples
- 25provisional
Optimism
Trails20.0 min
- rank
- #11
- samples
- 2provisional
Fastest Chainlink CCIP source chain by end-to-end delivery latency
BridgesArbitrum
Trails17.5 min
- rank
- #8
- samples
- 64provisional
Optimism
Leads17.5 min
- rank
- #7
- samples
- 9provisional
Fastest LayerZero source chain by end-to-end message delivery
BridgesArbitrum
Leads27.76 s
- p99
- 23.2 min
- rank
- #2
- samples
- 752
Optimism
Trails1.2 min
- p99
- 6.3 min
- rank
- #11
- samples
- 625
Fastest Axelar GMP source chain by end-to-end delivery
BridgesArbitrum
Leads19.4 min
- rank
- #6
- samples
- 16provisional
Optimism
Trails25.0 min
- rank
- #7
- samples
- 9provisional
Frequently asked questions
Arbitrum vs Optimism: which one is better?
Arbitrum and Optimism are compared on 7 shared OpenChainBench benchmarks. Arbitrum leads on Fastest L2 block time, live across Robinhood, Arbitrum, Base and 7 more. Optimism leads on Fastest Chainlink CCIP source chain by end-to-end delivery latency. See the live table on this page for every metric.
Which is faster, Arbitrum or Optimism?
On the Fastest L2 block time, live across Robinhood, Arbitrum, Base and 7 more benchmark, Arbitrum leads at 334 ms versus Optimism at 1.96 s. Live measurement is updated continuously by the OpenChainBench harness.
Which is faster, Arbitrum or Optimism?
On the Fastest Chainlink CCIP source chain by end-to-end delivery latency benchmark, Optimism leads at 17.5 min (provisional) versus Arbitrum at 17.5 min (provisional). Live measurement is updated continuously by the OpenChainBench harness.
How is the Arbitrum vs Optimism comparison measured?
Every benchmark on this page uses the same open methodology, published at https://openchainbench.com/methodology. Data is CC-BY-4.0. Measurement harnesses are MIT-licensed.
Related comparisons
How this pair was selected
Auto-generated pairs require: both providers in the same benchmark for seven consecutive days, at least 1000 samples per provider, observable third-party search demand, and a public /products/[slug] page on OCB. Editorially curated pairs (like this one) may publish early when search demand is high and data is accruing — panels with fewer than 100 samples are shown as provisional. The full pair ledger is versioned in the public repo.