Arbitrum vs Optimism: which has cheaper gas?
Optimism, decisively. It was cheaper than Arbitrum in 100% of the last 721 hours we observed — not most of the time, effectively all of the time. This is not a close call and there is no window in which the answer flips.
Priced as a swap at each chain's own mean fee, that is $0.0070 on Arbitrum against $0.0000022 on Optimism. Steadiness differs too: Arbitrum's fee spans 1.0× between its quiet and busy hours, Optimism's 49×. Arbitrum is the more predictable of the two, which can matter more than the average if you are pricing transactions in advance.
Both chains pay gas in ETH, so the gwei figures on this page are directly comparable as well as the dollar ones.
Both are rollups, so both figures here exclude the L1 data fee that settles their transactions on Ethereum. That omission is roughly symmetric, so the comparison holds even though the absolute numbers are understated.
Side by side, right now
| Transaction | Arbitrum | Optimism |
|---|---|---|
| Current fee | 0.020 gwei | 0.000000501 gwei |
| Send native token | $0.00098 | $0.000000024 |
| Send an ERC-20 token | $0.0030 | $0.000000076 |
| Swap on a DEX | $0.0070 | $0.00000017 |
Gas units are typical values, not measurements. Dollar figures use the current ETH price.
Over the last 30 days
- Hours compared
- 721
- Arbitrum cheaper in
- 0%
- Times the lead changed
- 0
- Mean swap cost gap
- $0.0070
Questions
Is Arbitrum or Optimism cheaper for gas?
Optimism was cheaper in 100% of the 721 hours compared over the last 30 days. The ranking did not flip once in that window.
Can I compare their gwei figures directly?
Both chains pay gas in ETH, so the gwei figures on this page are directly comparable as well as the dollar ones.
Are these the full fees?
Both are rollups, so both figures here exclude the L1 data fee that settles their transactions on Ethereum. That omission is roughly symmetric, so the comparison holds even though the absolute numbers are understated.