Okay, look. Most guides out there treat you like a total noob and drag on forever with screenshots every pixel. Or worse, they skip the part where your MetaMask just won't switch because you forgot to approve something. In my experience, that's what trips people up 90% of the time. You think you're done, but nope-network's added but you're still stuck on Ethereum Mainnet paying those crazy gas fees. Why does this matter? Because Arbitrum's whole deal is slashing those fees to like pennies. Gas on Arbitrum? We're talking ~0.0001 ETH per swap sometimes. Ethereum Mainnet? Buckle up for $10-50 easy.
So here's the real talk. I'm gonna walk you through adding Arbitrum One (the main one, not Nova-stick to this unless you know why you'd want the other) to MetaMask in legit 3 steps. But we'll go deeper after, 'cause once it's added, you gotta bridge funds or it'll just sit there empty. Sound familiar? Been there.
That's it for step 1. Super short, right? But here's the thing- if you're on mobile MetaMask app, it's a tad different. Tap the menu (three lines), then settings, networks, add network. I usually do this on desktop first to test. Why? Easier to see errors.
Sometimes MetaMask glitches and doesn't list Arbitrum in popular ones. No sweat. Just click "Add a network manually" at the bottom. We'll cover that in step 3 anyway.
Arbitrum's a Layer 2 for Ethereum. Basically, it bundles a ton of transactions off the main chain, so you get Ethereum security but fees drop like 10-100x. Swaps on Uniswap? Ethereum: $20 gas. Arbitrum: $0.20. Pretty much instant too. In my experience, DeFi yields are juicier there 'cause more liquidity pools without the fee wall.
But. There's Arbitrum One and Nova. One's for general stuff, Nova's cheaper but for high throughput games/NFTs. Start with One. You'll see.
Now, in that Add Network screen, scroll the popular custom networks. Arbitrum One's right there-Chain ID 42161 if you wanna verify.
| Detail | Value |
|---|---|
| Network Name | Arbitrum One |
| RPC URL | https://arb1.arbitrum.io/rpc |
| Chain ID | 42161 |
| Currency | ETH |
| Explorer | https://arbiscan.io/ |
Hit "Approve." Done. Switch to it in the dropdown. If balance shows 0 ETH, normal. No funds yet.
Pro tip: If "Add" doesn't appear, your MetaMask might be outdated. Update from the official site. Happened to me last week.
Or, lazier way-go to chainlist.org. Connect MetaMask, search "Arbitrum One," hit "Add to MetaMask." One click. I use this 80% of the time now. What's next? Testing it.
Don't bridge big yet. Grab like 0.001 ETH from a faucet if testnet, but mainnet? Buy cheap on an exchange like Coinbase, withdraw to your Arbitrum address. Wait, no-first bridge properly. We'll get there.
Common issue: "Network not working-RPC error." Fix? Clear MetaMask cache. Settings > Advanced > Reset account (keeps keys). Or try secondary RPC: https://rpc.ankr.com/arbitrum. Add as extra in network edit.
In my experience, Arbiscan.io is gold. Paste your address there after switching networks. Shows balance even if MetaMask lags.
Added? Great. But empty wallet sucks. Bridge from Ethereum Mainnet. Official: bridge.arbitrum.io.
Switch to Ethereum Mainnet first. Connect MetaMask. Select ETH (or USDC/USDT-works for ERC20s). Enter amount, say 0.05 ETH to start. Hit "Deposit." Approve twice: once for spend, once deposit. Gas? ~$5-20 on ETH side. Wait 10 mins-1hr. Check Arbitrum side.
Problem? "Insufficient funds for gas." Duh-need ETH on Mainnet. Buy via MetaMask ramp if fiat onramp's there.
On phone? Bridge site might not pop MetaMask right. Force desktop site in browser. Or use app's built in swap to Arbitrum-hit menu, swap, select Arbitrum.
Bridged USDC? Not in wallet? Normal. MetaMask hides custom tokens.
ARB token itself? 0x912CE59144191C1204E64559FE8253a0e49E6548. But buy on DEXes like Uniswap on Arbitrum.
Once funded, hit Uniswap.org, switch to Arbitrum. Swap ETH to USDC, gas ~$0.10. Or Velodrome for yields-farm ARB, fees dirt cheap.
Table of top swaps:
| DEX | Fee | Best For |
|---|---|---|
| Uniswap V3 | 0.3% / 0.05% | Stable swaps |
| Velodrome | 0.02% | Yield farming |
| GMX | 0.1% | Perps trading |
Honestly, start small. I lost 0.01 ETH once to wrong slippage-set 0.5% max.
MetaMask won't connect to dApp? Revoke approvals at revoke.cash. Scan for Arbitrum.
"Invalid network"? Delete and re add. Or hardware wallet? Connect Ledger/Trezor via settings-works.
Fees spiking? Arbitrum's still cheap, but peaks hit ~0.001 ETH. Wait or batch txns.
Security: Never share seed. Use Portfolio view for multi account. I got 5 accounts: one for Arbitrum farms.
One last: Updates happen. RPCs change? Check arbitrum.io docs. But this setup's solid as of now.