MEV Bot Simulator

WHAT IT DOES

MEV Bot Simulator lets you simulate a bundle of transactions to detect potential Maximal Extractable Value (MEV) opportunities. You provide a list of transactions (each with target address, calldata, and value), and the tool simulates their execution on the current chain state using eth_estimateGas. It reports which transactions succeed, their gas usage, and flags potential MEV opportunities. This is essential for developers building MEV bots, arbitrage strategies, or liquidation bots, as it allows testing bundles without risking real funds. It reads the current network chain ID from your wallet provider to ensure simulations are directed to the correct chain.

HOW TO USE

Connect your wallet using the "Connect" button (required for RPC access). Select the target network (Ethereum Mainnet, Sepolia, Polygon, BSC, Arbitrum, Optimism, and testnets are supported). Enter each transaction on a separate line in the format: to,data,value (address, hex calldata, value in wei). Optionally specify a block number for historical simulation. Click "Simulate bundle" — the tool will simulate each transaction sequentially using eth_estimateGas and display the results, including success/failure, gas usage, and a potential MEV opportunity indicator. The entire operation is read-only — no transactions are signed or sent.

TECHNICAL MECHANISM

The tool uses provider.estimateGas to simulate each transaction in the bundle sequentially. This mimics the execution of a bundle without actually sending transactions. Each transaction is simulated independently, with the state changes from previous transactions affecting subsequent ones. The tool tracks gas usage, success status, and error messages. It uses the provided block number or the latest block as the simulation context. The tool does not use eth_call for full return data — it focuses on gas estimation and success/failure detection. The tool uses ethers.js v5.7.2 to interact with the chain via the wallet's provider. All calls are view functions — no state is modified.

WHAT IT CANNOT SEE

The tool cannot guarantee that simulated results will match actual on-chain execution due to state changes between simulation and submission (e.g., block reorgs, mempool changes, frontrunning). It cannot detect all MEV opportunities without full mempool access — it only simulates the provided transactions. It cannot simulate complex cross-chain MEV. It is limited by RPC provider simulation capabilities and gas estimation accuracy. It cannot execute or submit bundles — only simulates. It cannot detect sandwich attacks without knowing the victim transaction's position. It cannot simulate bundles that require specific ordering or private mempool access.

PLEASE NOTE

This tool is for educational and research purposes. Always test strategies with small amounts before committing significant capital. The tool does not persist any data; all state is lost on page reload. EVM chains only.