Your private Testnet (forked from Mainnet), your own Explorer, Faucet and RPC

BuildBear Features:

Mainnet State

Create a Testnet that is forked from a range of Ethereum-compatible chains, including Ethereum, Polygon, Arbitrum, Optimism, Fantom, and Binance, at any block number.


Experience seamless exploration and easy debugging of your transactions on your Testnet with BuildBear's built-in explorer and in-built transaction tracer.


Minting native and popular ERC20 Tokens like USDC, DAI, USDT, BNB, BUSD, MATIC, WBTC, UNI, and AAVE has never been easier. With BuildBear's user-friendly faucet, you can mint tokens with just one click.

Unlock Advanced Customization

Run your standard testing and other scripts against BuildBear Testnets RPC with

  • Impersonate Account: Pretend to be another wallet that existed before your Testnet creation. This feature is particularly helpful for testing the effects of transactions in situations such as DAO voting, LP pool withdrawals, and more.

  • Deploy Contracts Beyond 24KB: Work on larger contracts without worrying about the contract size limit.

  • Mining Window: Set the mining interval between blocks to replicate a real blockchain environment.

  • Snapshot: Take a snapshot of the blockchain environment's state and execute transactions in the respective snapshot.