Token Lab Guides

How to Use the Bridge Helper to Move Funds Between Testnets

The Bridge Helper in Token Lab gives you quick, safe links to each network’s official faucet/bridge and block explorer, so you can get test ETH/MATIC on the right chain and keep building fast.

Quick note: Most testnets do not use cross-chain bridges the way mainnets do. The recommended path is to claim test funds on the destination chain via its official faucet, then switch your wallet to that chain.

Prerequisites

MetaMask (desktop browser extension or the MetaMask in-app browser on mobile).
An account connected in Token Lab (use the Connect Wallet button).
Know which testnet you’re building on: Ethereum Sepolia, Polygon Amoy, Base Sepolia, or Arbitrum Sepolia.

Bridge Helper Step-by-Step

Open Token Lab and scroll to the card titled
“Bridge Helper – Move Funds Between Testnets”.
In the From dropdown, choose where you currently have funds (for reference). In the To dropdown, choose your
destination testnet (the chain you want to build or deploy on).
Click Open Destination Faucet/Bridge. This takes you to the official faucet or bridge page for that testnet. Follow
the on-screen steps (many faucets require a GitHub/X login or have rate limits).
After claiming, click Open Destination Explorer to confirm the test transaction reached your address (paste your wallet address).
In MetaMask, switch your network to the same destination testnet you just funded. Back in Token Lab, you can now deploy,
transfer, approve allowances, or read token data on that chain.

Tip: If MetaMask doesn’t have a testnet added yet, use the Switch Network button at the top of Token Lab.
If the chain isn’t found, Token Lab will attempt to add the network for you automatically.

Why faucets instead of cross-chain bridges?

Testnets are designed for development. They often don’t maintain shared liquidity or canonical bridges. Getting native test ETH/MATIC
from the official faucet is the fastest, safest route. For mainnet bridging, use reputable multi-bridge aggregators; for
testnets, use faucets.

Supported Testnets in Token Lab

Ethereum Sepolia — Faucet + Explorer
Polygon Amoy — Faucet + Explorer
Base Sepolia — Faucet + Explorer
Arbitrum Sepolia — Faucet + Explorer

We’ll add more networks over time. If a faucet is rate-limited, try again later or use a different reputable faucet.

Troubleshooting

“No wallet detected” on mobile

Open Token Lab inside the MetaMask in-app browser (there’s a link right on the page). Normal mobile browsers can’t always
inject a wallet provider.

Faucet says “rate limited” or “not eligible”

Many faucets limit requests per wallet or account. Wait and retry, or try a different official faucet for the same network.

I claimed funds but my balance is 0

Make sure MetaMask is switched to the same destination testnet you claimed on. Also verify the address on the destination
Explorer link provided by the Bridge Helper.

Can I bridge testnet tokens cross-chain?

Typically no. Testnets rarely support reliable cross-chain bridges. Use the faucet for the target network, then switch your wallet to that chain.

Next Steps in Token Lab

Create a token with the No-Code Wizard and deploy via Remix.
Use Transfer to send your test tokens to another address.
Use Approve & Allowance to simulate dApp permissions.
Use Peek a Token to read metadata on any ERC-20.