Add Arbitrum Sepolia to MetaMask
Arbitrum’s test rollup, funded by bridging Sepolia ETH.
Opens a MetaMask confirmation. Nothing is added until you approve it.
Network parameters
If you prefer to type them in by hand — MetaMask → network selector → Add a custom network. Checked 2026-09-14.
Arbitrum Sepolia https://sepolia-rollup.arbitrum.io/rpc 421614 ETH https://sepolia.arbiscan.io Adding it manually, step by step
- Unlock MetaMask and click the network name in the top-left corner.
- Choose Add a custom network (older versions: Settings → Networks → Add network → Add a network manually).
- Paste the six values from the box above into the matching fields.
- Press Save. MetaMask queries the RPC and checks that it really serves chain ID 421614.
- Select Arbitrum Sepolia from the network list. Your address stays the same — only the balances change.
If something goes wrong
“Chain ID returned by the network does not match”
The RPC URL points at a different chain than the ID you entered. Re-copy the RPC URL from this page; guides that were written years ago often list endpoints that have since been repurposed.
“Could not fetch chain ID” or an endless spinner
The public node is rate-limiting you or is temporarily down. Use the backup RPC URL above, or pick another public endpoint for this chain.
The network was added but my balance is zero
Balances are per-network. Holding ETH on an exchange or on another chain does not put it here — it has to be withdrawn or bridged to Arbitrum Sepolia specifically.
Getting test ETH
More on the testnet faucet list.