B3 Sepolia Testnet is an Ethereum Sepolia–compatible, EVM-based test environment for the B3 ecosystem that uses ETH for gas and mirrors production behavior for safe iteration. Primary use cases include end-to-end testing of B3’s cross-chain bridge flows (lock/mint/burn/redeem), deploying and verifying smart contracts, wallet and dApp integration, and performance benchmarking before mainnet release.
B3 Sepolia is bridge-first: it ships with ready-to-use faucet, RPC/explorer access, test assets, and reference contracts aligned with the B3 cross-chain bridge to streamline integration and QA. Performance is in line with Ethereum Sepolia—~12s block times, practical throughput in the low single digits with capacity near 10–15 TPS, and typical gas prices around 1–3 gwei (simple transfers ≈21k gas ≈0.000021–0.000063 ETH). Activity is lower and more predictable than mainnet, enabling consistent latency and fee measurements for cross-chain workflows; see https://b3.fun for live metrics and endpoints.
B3 Sepolia Testnet uses ETH as the gas token for transaction fees. You can obtain ETH by bridging from other chains or purchasing using thirdweb Bridge, or through faucets (for testnet).
To bridge ETH to B3 Sepolia Testnet, connect your wallet to thirdweb bridge, select your source chain, choose the token you want to bridge, select B3 Sepolia Testnet as the destination, enter the amount, and confirm the transaction. The bridge will handle the cross-chain transfer instantly.
To build on B3 Sepolia Testnet you can use thirdweb, which provides an easy way to build, monetize and scale your apps, games or agents. You can find detailed guides and documentation on https://portal.thirdweb.com to get started quickly.
To add B3 Sepolia Testnet to your wallet, you can connect your wallet and click on [Add to Wallet] button at the top of the page. Alternatively, you can add the network manually using the RPC URL and chain details and add it to your wallet's network settings.
To send ETH on B3 Sepolia Testnet, ensure your wallet is connected to the B3 Sepolia Testnet network, enter the recipient's address, specify the amount of ETH to send, review the gas fee, and confirm the transaction in your wallet.