This bridge is specifically for testnet purposes. Use free testnet ETH to test your applications before deploying to mainnet.

How to Bridge

1

Visit the Testnet Bridge

Go to testnet.bridge.b3.fun to access the official testnet bridge interface.
2

Connect your Wallet

Connect your wallet (MetaMask, Coinbase Wallet, etc.) to the bridge interface.
Make sure your wallet is connected to either Base Sepolia or B3 Testnet depending on which direction you want to bridge.
3

Choose Bridge Direction

Select whether you want to:
  • Deposit: Bring funds from Base Sepolia → B3 Testnet
  • Withdraw: Bridge back from B3 Testnet → Base Sepolia
Click either the Deposit or Withdraw tabs accordingly.
5

Confirm Transaction

Click “Deposit” (or “Withdraw”) and confirm the transaction prompt that appears in your wallet.
Double-check that you’re on the correct testnet and using testnet ETH, not mainnet funds.
6

Wait for Completion

Wait a few minutes for the bridge process to complete. You can check the status in your “History” tab.
Your testnet ETH will appear in your wallet on the destination network within a few minutes.

Network Information

Base Sepolia Testnet

B3 Sepolia Testnet

Testnet Resources

Additional Faucets

If you need testnet ETH for development, here are some reliable faucet options:

Troubleshooting

Development Workflow

1

Get Base Sepolia ETH

Use a Base Sepolia faucet to get free testnet ETH.
2

Bridge to B3 Testnet

Use the testnet bridge to move ETH from Base Sepolia to B3 Testnet.
3

Deploy and Test

Deploy your contracts and test your applications on B3 Testnet.
4

Ready for Mainnet

When testing is complete, deploy to B3 Mainnet using the mainnet bridge.