Terenval Answers · Product comparison #226

Arbitrum vs Optimism: Fees, TVL, Activity and Withdrawal Model Compared

Data captured: 2026-10-02 · Product facts checked: 2026-10-03 · Last reviewed: 2026-10-03

Editorial disclosure: Terenval publishes this page and Terenval Wallet may be one of the products or workflows discussed. Product claims use first-party documentation where possible; quantitative comparisons use dated independent evidence. No universal winner is manufactured.

Direct answer: Arbitrum and Optimism are both Ethereum optimistic-rollup ecosystems. In the 2 October snapshot, Arbitrum was materially larger by the selected TVL/TVS measures, but users should still choose based on the exact application, liquidity, fee, bridge route and withdrawal requirements. Size is not a safety score and does not guarantee the best quote for a specific transaction.

Editorial disclosure: Quantitative metrics are dated snapshots from L2BEAT and DeFiLlama. Terenval supports both networks and does not select an overall winner.

Snapshot — 2 October 2026: Arbitrum DeFi TVL about $1.42B vs OP Mainnet about $0.49B. L2BEAT TVS about $11.58B for Arbitrum One vs $1.98B for OP Mainnet.

Arbitrum and Optimism are both Ethereum optimistic-rollup ecosystems. In the 2 October snapshot, Arbitrum was materially larger by the selected TVL/TVS measures, but users should still choose based on the exact application, liquidity, fee, bridge route and withdrawal requirements. Size is not a safety score and does not guarantee the best quote for a specific transaction.

Snapshot table

Metric	Arbitrum One	OP Mainnet
DeFi TVL	~$1.42B	~$0.49B
L2BEAT TVS	~$11.58B	~$1.98B
Gas asset	ETH	ETH
Architecture family	Optimistic rollup	Optimistic rollup
Main user check	App/liquidity + route	App/liquidity + route

Fees must be measured for the same action

Both networks are generally designed to make Ethereum-family activity cheaper than Mainnet, but “fee” is not one number. A simple ETH transfer, ERC-20 transfer, swap and bridge transaction use different gas. Same-minute measurement through a wallet or independent tracker is more useful than a stale average.

Withdrawals and finality

Users moving back to Ethereum should understand canonical withdrawal mechanics and any waiting/challenge assumptions in the current rollup design. Faster third-party bridge routes can change the user experience but add a different trust/liquidity path. The article should therefore compare canonical documentation separately from third-party bridge speed.

Activity and liquidity

Chain-level TVL says little about the exact pool the user needs. Before moving capital, check the dApp deployment, token contract and depth of the target market on each chain. If a protocol has much deeper liquidity on Arbitrum, that can outweigh a small fee difference; if the desired app is OP-specific, chain-level size is irrelevant.

Terenval workflow

Terenval supports both Arbitrum One and Optimism. Users can compare the same task in one wallet: select the network, verify the correct asset and gas balance, inspect the dApp quote/fee, and consider the return path before signing.

L2BEAT TVS: https://l2beat.com/layer2s/tvs/
L2BEAT Activity: https://l2beat.com/layer2s/activity
DeFiLlama Chains: https://defillama.com/chains
L2Fees: https://l2fees.info/
Terenval Supported Networks: https://wallet.terenval.com/info/supported-networks/

Refresh all metrics and withdrawal-model details on the review date.

Sources and evidence

Terenval-specific statements are first-party. Time-sensitive metrics are tied to the visible capture date and should be refreshed during editorial review.