Uniswap Gas Fee on Arbitrum
How much does a Uniswap swap cost on Arbitrum right now? The card below shows today's live USD fee for a typical V3 swap on Arbitrum One — calculated from the chain's current gas price and the live ETH/USD rate. It's the same Uniswap, at roughly a tenth to a twentieth of the mainnet price.
Live Uniswap swap cost on Arbitrum
~150,000 gas · 0.0200 Gwei · ETH ≈ $1,669.24
Total fee
$0.005008
Arbitrum Nitro bundles the parent-chain calldata/poster fee into eth_gasPrice — the displayed cost is the full wallet fee.
Arbitrum vs mainnet — the same swap, side by side
A Uniswap swap is the same ~150,000 gas units of work wherever you run it. What changes is the price of that gas. On Ethereum mainnet you pay full L1 gas for every step; on Arbitrum you pay cheap rollup execution plus an amortized slice of the batch that Arbitrum posts back to Ethereum. Here's the live mainnet figure for the identical swap, so you can see the gap for yourself:
Live Uniswap swap (mainnet) cost
150,000 gas units · ETH ≈ $1,669
Standard
$0.0964
0.385 Gwei
Lowest tier that confirms in a few minutes.
Fast
$0.1566
0.625 Gwei
Default wallet tier — confirms in about a minute.
Rapid
$0.4037
1.61 Gwei
Top priority — confirms in under 30 seconds.
Base fee right now: 0.356 Gwei. Tier prices add the average priority tip seen in recent blocks. Wallets often pad estimates by 10–30%, so your actual quote may be a bit higher.
On a normal week the Arbitrum swap above runs 10–20x cheaper than the mainnet card. The gap widens during mainnet congestion — when a big mint or listing pushes L1 gas up, mainnet swaps can hit $20–50 while the Arbitrum cost barely moves, because only the small posting share is exposed to L1 prices.
How Arbitrum prices a swap
Arbitrum runs the Nitro stack. Two things make a swap cheap, and one subtlety is worth knowing:
- Execution is cheap. The actual swap computation — pool lookups, tick math, token transfers — runs on Arbitrum's own execution layer at a tiny fraction of mainnet gas prices.
- L1 posting is shared. Arbitrum batches thousands of transactions and posts them to Ethereum together. Your swap pays only its slice of that compressed batch, not a full L1 transaction.
- It's already bundled. Unlike Base or Optimism — where the L1 data fee is a separate, dominant line item — Arbitrum folds the posting cost into its
eth_gasPrice. So the single number on the card is the full fee, no hidden L1 surcharge to add.
One consequence: Arbitrum swap costs rise when Ethereum mainnet gas spikes, because the posting share is priced in L1 terms — just far less than paying full mainnet gas directly.
Getting ETH onto Arbitrum to swap
The catch with any L2 is the round trip. To swap on Arbitrum you need ETH on Arbitrum for gas, which means bridging from mainnet first — and the bridge transaction itself pays mainnet gas. If you're moving funds specifically to make one small swap, the bridge cost can outweigh the savings. The math flips in your favor when you're going to make several swaps, or you're already active on Arbitrum.
See the live cheapest bridge to Arbitrum comparison to minimize that one-time cost, and the Ethereum → Arbitrum bridge fees breakdown for what to expect.
Arbitrum vs the other L2s for a Uniswap swap
Uniswap is deployed on every major L2, and the cheapest one shifts week to week. Rough shape of the field:
- • Base and Optimism (OP Stack) — frequently the cheapest, but their L1 data fee swings with mainnet, so the total is more volatile day to day.
- • Arbitrum — consistently low and the deepest liquidity of the L2s, which means less price impact on larger swaps.
- • Polygon — often a fraction of a cent, but it's a sidechain with a different security model than the rollups.
For deeper pools and large trades, Arbitrum's liquidity usually wins on all-in cost even when its gas isn't the rock-bottom number. For tiny swaps where gas is the whole cost, check the live table before bridging.
Frequently asked questions
How much does a Uniswap swap cost on Arbitrum right now?
The live figure in the card above is the current cost of a typical Uniswap V3 swap on Arbitrum One, updated every minute. It is usually well under $1 — most weeks a few cents to ~$0.30 — versus several dollars on Ethereum mainnet.
Why is Uniswap so much cheaper on Arbitrum than on Ethereum?
Arbitrum is an optimistic rollup. It executes your swap off the main Ethereum chain and posts only a compressed summary back to L1. You pay for cheap L2 execution plus a small share of the batched L1 posting cost, instead of paying full mainnet gas for every step of the swap.
Is the Uniswap interface the same on Arbitrum?
Yes. It is the same Uniswap protocol and the same app.uniswap.org interface — you just switch your wallet network to Arbitrum One. Your ETH for gas must be bridged to Arbitrum first; the gas token is still ETH.
Does an Arbitrum swap have a separate L1 data fee like Base?
Not as a separate line item. Arbitrum Nitro bundles the parent-chain (L1) calldata-posting cost directly into its gas price, so the single figure you see is already the full wallet fee. On OP-stack chains like Base and Optimism the L1 data fee is shown separately because it dominates the total.
Do I still pay a token approval fee on Arbitrum?
The first time you swap a given ERC-20, yes — but it is cheap. An approve() on Arbitrum typically costs a few cents versus several dollars on mainnet. The modern Uniswap UI also routes through Permit2, which folds the approval into the swap so first-time swaps cost roughly the same as repeat ones.
Is Arbitrum the cheapest L2 for Uniswap?
It is consistently cheap, but Base and Optimism trade the cheapest-swap crown week to week, and Polygon is often a fraction of a cent. Use the live L2 comparison to see which is cheapest at this moment before you bridge.
Compare every L2 before you bridge.
Live swap and transfer costs across Arbitrum, Base, Optimism, and Polygon in one table — so you bridge to whichever is cheapest right now.